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Current Products

CVS4200C Indoor Stationary Water Sampler

The CVS4200C is a stationary water sampler designed for indoor use. The sampler uses reliable, long-lasting, vacuum technology. This sampling method results in faster sample...

CVS4200D Indoor Stationary Water Sampler

The CVS4200D is a stationary water sampler designed for indoor use. The sampler uses reliable, long-lasting, vacuum technology. This sampling method results in faster sample...

BVS4300C Outdoor Stationary Water Sampler

The BVS4300C is a stationary water sampler designed for outdoor use. It is housed in a protective steel enclosure to resist harsh conditions. The sampler...

BVS4300D Outdoor Stationary Water Sampler

The BVS4300D is a discrete sampler that places each sample into a separate container. This stationary water sampler is designed for outdoor use. It is...

PVS4100C Composite Water Sampler

The PVS4100C is a deluxe ac-powered water sampler that deposits its water samples into one container. It uses our biggest sampler pump allowing it to...

PVS4100D Discrete Water Sampler

The PVS4100D is a deluxe ac-powered water sampler that deposits its water samples into 24 containers. It uses our biggest sampler pump allowing it to...

PVS4120C Portable Composite Water Sampler

The PVS4120C is a lightweight, portable, battery-operated water sampler that deposits its water samples into one container. It includes a programmable controller with 16-key intuitive...

PVS4120D Portable Discrete Water Sampler

The PVS4120D is a light-weight, portable, battery-operated water sampler that deposits its water samples into 24 containers. It includes a programmable controller with 16-key intuitive...

PVS4151C Portable Composite Water Sampler

The PVS4151C is a portable, battery-operated water sampler designed for easy transport. It deposits its water samples into one 9 liter container. The PVS4151C includes...

Fundamentals of Automatic Water Samplers

Automatic water samplers collect samples from a water source without requiring human intervention each time a sample is needed. The samplers can be programmed to collect samples at different intervals for different durations. The collected water samples can be evaluated immediately onsite, or they can be stored and transported to a facility's laboratory for analysis.

Facilities in many industries use automatic water samplers to help meet their required water quality standards. These facilities have seen a trend in recent years toward more heavily regulated water quality governance, more detailed permit requirements, and more thorough water sampling documentation.

Automatic water samplers provide facilities with detailed sampling data that is reportable and defensible. In addition, facilities have discovered several other benefits of using automatic water samplers:

  • Reduced costs through labor savings
  • Minimized potential for human error in sampling technique
  • Improved water sampling consistency
  • Fewer safety risks to sampling personnel

By efficiently collecting and preserving water samples, automatic water samplers help provide accurate water quality data. This data aids facilities in making more informed decisions. Ultimately, these decisions can affect the safety and health of humans and other organisms that depend on water as a vital resource.

Manual vs. Automatic Sampling

Before reviewing the different types of automatic water samplers, it may be helpful to first understand how automatic water sampling is different from manual water sampling.

Manual sampling, sometimes referred to as performing a "manual grab," requires minimal equipment. Low-tech manual sampling is done by simply placing a sample container into a water source, or its flow, and collecting a sample. Manual sampling can be a cost-effective solution for a facility with short-term monitoring programs or very infrequent sampling.

Facilities that conduct frequent sampling in multiple, distant locations often find manual sampling to be inconvenient. Manual sampling requires trained sampling personnel to be available to collect samples. In addition, some site environments pose safety concerns to sampling personnel. In these situations, facilities often prefer automatic sampling.

Automatic sampling uses a preprogrammed powered water sampler to collect water samples on a time-based or event-triggered schedule. For example, a water sampler can be programmed to collect water samples every day at 6 a.m. and 6 p.m. (time based), or a sampler can be programmed to start sampling every time rain begins to fall (event triggered).

Because of the ability to program sampling and the convenience offered, automatic sampling is often preferred to manual sampling. Automatic sampling offers the convenience of unattended, long-term monitoring, thereby reducing the time and cost associated with frequent manual sampling. In addition, automatic sampling minimizes the possibility of human error in sample collection.

Automatic Water Sampler Components

Automatic water samplers vary considerably in their technology and application, but they share the same components. These components are briefly described in the following sections.

Controller

The controller, or "brain" of the water sampler, is used to program and control the sampler. The controller usually has a keypad for programming the sampler and an LCD for providing status feedback.

Pump system

The pump system moves fluid from the water source into the water sampler to collect the samples. Water samplers commonly use either a peristaltic or vacuum pump.

Sample containers

Sample containers hold water samples until they are evaluated or analyzed. A water sampler may deposit samples into a single sample container (composite sampling) or into individual sample containers (discrete sampling).

Cooling chamber or refrigerator

If samples must be chilled, a portable sampler's cooling chamber or a stationary sampler's refrigerator is used.

Automatic Water Sampler Types and Characteristics

The following water sampler types and characteristics, as well as their advantages and disadvantages, are described in these sections:

  • Peristaltic pump and vacuum pump technology
  • Composite and discrete sampling
  • Portable and stationary water samplers
  • Chilled and non-chilled water samples

Peristaltic pump and vacuum pump technology

Automatic water samplers use either peristaltic pump or vacuum pump technology. Both pump technologies move fluid from the water source into the water sampler so that the fluid can be collected.

Peristaltic pump

In a peristaltic pump, the flexible tubing is squeezed to make the fluid flow through the tubing. The following are the steps used to measure and collect a water sample using peristaltic pump technology:

  1. The pump rotates in the reverse direction. By pumping air through the system, the pump cleans the intake tubing of residual liquid and obstructions. Alternatively, personnel can manually switch the intake tubing from the water source to a container of clean rinsing water to purge the line. They can then switch the intake tubing back to the water source.
  2. The pump rotates in the forward direction and pumps fluid from the water source into the intake tubing.
  3. As the controller detects the fluid in the intake tubing, the controller determines how many pump revolutions, or "pump counts," are required to attain the programmed sample volume.
  4. To reach the required sample volume, the pump rotates forward for each pump count. Each time the pump rotates forward, the pump tubing is squeezed to move the fluid along.
  5. As the required pump counts are completed, the sample is deposited in the sample container.
  6. The pump rotates in the reverse direction. By pumping air through the system, the pump cleans the intake tubing of residual liquid and obstructions. Alternatively, personnel can manually switch the intake tubing from the water source to a container of clean rinsing water to purge the line. They can then switch the intake tubing back to the water source.
Advantages
  • Typically, a peristaltic pump sampler requires less power to run than a vacuum pump sampler.
  • Because no wires stick out from a peristaltic pump sampler, the sampler has a tidy appearance.
  • Peristaltic pump samplers may be less expensive than vacuum pump samplers.
Disadvantages
  • Repeatedly squeezing the tubing to move the fluid through a peristaltic pump sampler causes the tubing to wear out, the squeezing to become less tight, and the sample volumes to vary. Consequently, a precise sample volume cannot be guaranteed from one sample to the next.
  • When the pump tubing is squeezed in a peristaltic pump sampler, any suspended solids in the sample can be squeezed, and altered, as well. The solids can also stick to the lining of the tubing. Thus, the sample may not be truly representative of the water source at the time of sampling.
  • Many peristaltic pump samplers are not compatible with larger tubing. When smaller tubing is used, it can become blocked by any large suspended solids in the fluid, or the large solids may be screened out.
  • Peristaltic pump samplers typically provide less velocity than vacuum pump samplers. With less velocity, particles are not held in suspension as well and may settle, causing the water sample to not be truly representative of the water source.
Vacuum pump

In a vacuum pump, negative pressure creates a vacuum that makes the fluid flow. The following are the steps used to measure and collect a sample using vacuum pump technology:

  1. A non-invasive, high-pressure purge of air is used to clean the intake assembly of residual liquid and obstructions.
  2. Using the vacuum, fluid from the water source is drawn through the intake hose and into the metering chamber.
  3. After the metering chamber is filled, the system is pressurized. Excess fluid is released until the correct sample amount is obtained.
  4. The sample, now at its correct volume, is deposited into the sample container.
  5. A non-invasive, high-pressure purge of air is used to clean the intake assembly of residual liquid and obstructions.
Advantages
  • A vacuum pump sampler's metering chamber helps ensure that sample volumes are precise and repeatable from sample to sample. If the control volume is set at a level that does not greatly exceed the required sample volume, the suspended particles do not settle and affect the sample's representativeness of the water source.
  • Because the tubing in a vacuum pump sampler is not squeezed repeatedly, it does not wear out as quickly as the tubing in a peristaltic pump sampler. In addition, because there is no squeezing, any suspended solids in the fluid are not altered.
  • Unlike peristaltic pump samplers, vacuum pump samplers are typically compatible with larger tubing. Larger tubing allows larger suspended solids to pass through. Smaller tubing, on the other hand, may become blocked by larger solids.
  • Compared to peristaltic pump samplers, vacuum pump samplers typically provide greater velocity. Greater velocity holds particles in suspension better and provides a more representative sample.
  • The cleansing air pumped through a vacuum pump sampler is under higher pressure than the air pumped through a peristaltic pump sampler. The higher-pressure air may provide more thorough cleaning and less chance of residual liquid from a previous sample.
Disadvantages
  • Typically, a vacuum pump sampler requires more power to run than a peristaltic pump sampler.

Composite and discrete sampling

Automatic water samplers can collect either composite or discrete samples over time. In composite sampling, individual sample volumes are deposited into a single large sample container. In discrete sampling, individual sample volumes are deposited into individual small sample containers.

Composite

Composite sampling can provide a representative water sample for a certain period. Over time, a composite sampler deposits individual sample volumes into a single large sample container. The size of the sample container can vary. For example, a composite sampler could be used with a single 9 L container or a single 20 L container.

Advantages
  • A composite sampler is able to produce a water sample that represents the average water quality for a specified period.
  • A composite sampler is less expensive than a discrete sampler.
Disadvantages
  • Because multiple water samples in a composite sampler are combined in a single sample container, sampling personnel cannot pinpoint and track changes in a water source as precisely as with a discrete sampler.
Discrete

Discrete sampling is used to acquire multiple, distinct water samples over time. A discrete sampler deposits each sample volume into its own separate sample container. A stepper with distributor arm rotates among the sample containers and fills them one at a time.

The sample containers used in a discrete sampler are available in a variety of sizes, but a discrete sampler typically contains a set of sample containers that are uniform in size. For example, a discrete sampler could use a set of 0.5 L containers, a set of 1 L containers, or a set of 2 L containers. Because the space to hold the sample containers is finite, either many smaller containers or fewer larger containers can be used.

A variation on discrete sampling is multi-composite sampling. Multi-composite sampling uses a discrete sampler to deposit multiple sample volumes into a single sample container. The distributor arm then rotates to fill the next container in the same manner.

Advantages
  • Because water samples in a discrete sampler are kept separate, sampling personnel can more precisely pinpoint and track changes in a water source than they can using a composite sampler.
Disadvantages
  • Because of the multiple sample containers used, a discrete sampler requires more maintenance to collect, clean, and change out the sample containers.
  • A discrete sampler is more expensive than a composite sampler.

Portable and stationary water samplers

Automatic water samplers are either portable or stationary. A portable water sampler can be moved easily from one site location to another. A stationary water sampler is designed to remain at a fixed installation. Both types of water samplers can be used to collect either composite or discrete samples.

Portable

As the term "portable" implies, a portable sampler is one that can be moved easily from one sampling site to another. (If required, however, a portable sampler can remain at a single site.) Because of their smaller size, portable samplers may also be used at space-restricted locations.

Advantages
  • A portable sampler can be moved easily among multiple sites that require infrequent sampling.
  • Portable samplers are smaller and weigh less than stationary samplers. Portable samplers may be appropriate for sampling sites that have space restrictions, such as manholes, or sites that require strapping a water sampler to a pole.
  • Because a portable sampler requires less power than a stationary sampler, a portable sampler may be able to use solar power, batteries, or both.
Disadvantages
  • Because a portable sampler uses ice rather than a refrigerator to chill samples, samples cannot be kept chilled for an extended period without frequent replacement of the ice. Consequently, sampling personnel need to replace the ice routinely or retrieve the samples before their temperature increases significantly due to ice melt.
  • If a portable sampler is inactive for extended periods, an additional power source may be needed to ensure future sampling operation.
  • Because of its portability, a portable sampler may be stolen.
Stationary

As the term "stationary" implies, a stationary sampler is designed to remain at a particular sampling site for an extended period. Although a stationary sampler is often considered a permanent fixture, it can be moved from a site.

Advantages
  • A stationary sampler can be equipped with a locked cabinet to deter tampering with the controller or sample containers.
  • If a stationary sampler has a refrigerator (powered by an ac power source), the sampler preserves chilled samples for an extended period without the need for sampling personnel to replace ice. 
  • A stationary sampler can be left unattended, at a site that requires frequent sampling, with less likelihood that it will be stolen.
Disadvantages
  • A stationary sampler cannot be easily transported to many sites.
  • A stationary sampler typically requires an ac power source. If desired, a backup battery may be used as well.

Chilled and non-chilled water samples

Automatic water samplers may or may not chill their collected water samples. Chilling options are available using either a portable or stationary sampler; however, the samplers' methods for chilling samples are different.

Chilled

Chilling water samples significantly reduces the rate at which chemical reactions and biological phase changes occur in the samples. Consequently, water samples are more accurate and representative of their water sources.

Stationary samplers typically chill samples using a refrigerator. When a refrigerator, powered by an ac power source, is used in a water sampling system, samples can be kept chilled for months. Water samples are typically kept at a temperature of 4 degrees Celsius (39 degrees Fahrenheit).

Portable samplers typically chill samples using ice placed in a cooling chamber. Many portable samplers are equipped with a cooling chamber in their base. The cooling chamber has an insulated cavity that can be filled with cubed or crushed ice. The use of ice can keep samples chilled for up to 24 hours prior to the samples' collection for analysis.

Advantages
  • A refrigerator or cooling chamber can help prevent samples from undergoing significant biological or chemical change due to temperature change. Consequently, the samples' integrity is maintained, providing a more accurate representation of the water source.
  • A refrigerator or cooling chamber may be used to meet a governing body's sampling requirements for maintaining a sample at a specific temperature prior to analysis.
Disadvantages
  • When ice is used in the cooling chamber of a portable sampler, sampling personnel need to replace the ice or collect the samples before the samples' temperature increases significantly due to ice melt. In addition, sampling personnel may need to replace the ice in preparation for the next sampling round.
  • A stationary sampler with a refrigerator requires an ac power source.
  • Due to its size, a stationary sampler with a refrigerator may exceed the dimensional limitations of a sampling site.
Non-chilled

Stationary samplers without a refrigerator, as well as portable samplers used without ice, do not chill their water samples. Consequently, the water samples may be more susceptible to biological or chemical changes caused by changes in the ambient temperature.

Advantages
  • Chilling is not necessary for certain water sample substances that are unaffected by temperature changes. Chilling is also unnecessary when water sample evaluation or analysis is conducted immediately after the sample collection.
  • When samples do not need to be chilled, it is not necessary to purchase ice or a refrigerator.
Disadvantages
  • If a chilling method is not used, a consistent water sample temperature may not be maintained. A change in water sample temperature may cause water samples to undergo significant biological or chemical change. Consequently, non-chilled samples may no longer serve as an accurate representation of the water source.

In Review

The intention of this section is to provide a general overview of automatic water samplers. More information, including answers to common questions, can be found in the other tabs at the top of this page.

Answers to general, technical, or sales questions can be attained by completing the appropriate question form online:

Representatives from Campbell Scientific, Inc., may also be queried via phone or email.

Links

The following list provides some additional resources regarding water sampling and automatic water samplers:

Water Sampler FAQs

How are automatic water samplers affected by altitude?

Automatic water samplers are typically tested at sea level, and their performance varies depending on the altitude at which they are actually used. Higher altitudes decrease the vertical lift capabilities of samplers. For high-altitude needs, consult with a water sampler supplier to build an appropriate system.

What type of analysis can be done at the water sampler site?

In many instances, a water sampler is used to collect water samples and preserve them until they are transported to a laboratory for analysis. In other instances, immediate data from the water sampler is required. For example, water level, temperature, pH, conductivity, turbidity, flow, and dissolved oxygen are some examples of measurements analyzed onsite. Measurement data for either immediate or laboratory analysis can be acquired using specialized sensors with a datalogger. 

What communications options can be used with a water sampler?

There are several communications options available, such as telephone modems (including cellular and voice-synthesized), short haul modems, radio transceivers, satellite transmitters, and Ethernet interfaces. For example, a water sampling system can be programmed to send alarms or report site conditions. As another example, an automated phone call can inform personnel that a sample was just taken, thereby eliminating the need to drive to a remote location for verification. 

How can more data for water analysis be acquired?

When a facility uses an automatic water sampler with a datalogger, the facility has more flexibility. For example, a facility can use various sensors to take many different measurements at the same time. These measurements can be analyzed onsite, in a laboratory, or at both locations.

How can data be communicated from the water sampler to an offsite location?

When a datalogger is used with a water sampler, historical data can be stored, and complex calculations can be computed. When a third component, a communications peripheral, is interfaced with the datalogger, then the data and calculations can be transmitted offsite automatically for viewing in near real time. This information can be downloaded to a computer for extended storage, further analysis, sharing, and reporting. 

What affects the horizontal transport velocity for water sampling?

In a location with a fast-moving water source, samples need to be taken at a fast enough speed to ensure an accurate representation of the water source. This situation may require a larger pump to maintain the necessary velocity. A larger pump may also be necessary if there is a long horizontal distance that the fluid must travel between the water source and the water sampler.

In general, the following statements are true regarding horizontal velocity:

  • Increasing the inner diameter of the tubing decreases the velocity. (The larger the tubing, the slower the fluid flows.)
  • Decreasing the pump power decreases the velocity. (The smaller the pump, the slower the fluid flows.)
  • Increasing the horizontal distance between the water source and the water sampler decreases the velocity. (The farther the distance, the slower the fluid flows.)
What is the relationship between vertical lift and velocity for water sampling?

As the vertical lift (the vertical distance between the level of the water source and the water sampler’s pump) increases, the speed of the fluid through the sampling system decreases. Consequently, greater speed is needed to compensate for a larger gain in height and to preserve a more representative sampling of large particles and suspended solids. To maintain the necessary velocity, a larger pump may be required.

In general, the following statements are true regarding vertical velocity:

  • Increasing the inner diameter of the tubing decreases the velocity. (The larger the tubing, the slower the fluid flows.)
  • Decreasing the pump power decreases the velocity. (The smaller the pump, the slower the fluid flows.)
  • Increasing the vertical lift decreases the velocity. (The higher the fluid needs to travel, the slower the fluid flows.)
  • Increasing the altitude at which the water sampler is located decreases the velocity. (The higher the altitude, the slower the fluid flows.)
How do horizontal and vertical distances affect water sampling?

Horizontal and vertical distances should not be considered separately because they work together to affect velocity. As the liquid moves across and up, it must be pumped with enough force to maintain the desired velocity for representative sampling. 

In what environments can automatic water samplers be used?

Water sampling systems can be designed to endure harsh or inclement environments that are unsuitable for water sampling personnel. Water samplers maintain their measurement reliability in challenging environments by using any of several optional devices. These devices include steel enclosures, locking mechanisms, refrigerators or cooling chambers, forced-air heaters, extra insulation, circulation fans, and external power supplies. 

How are automatic water samplers used?

Water samplers are used as a tool to collect water samples for measurement and analysis in water quality monitoring programs. The specific use of water samplers is often determined by the intended use of the water source and the applicable water quality standards. For example, water quality is often considered in relation to ecosystems, human contact (such as swimming), drinking water, and irrigation. Water whose quality is appropriate for one use may not be considered appropriate for another use.

Where are automatic water samplers used?

Water samplers can be used in a variety of settings, including the following:

  • Aquaculture operations
  • Caves
  • Containers
  • Dams
  • Dangerous environments
  • Fast-moving water sources
  • Fisheries
  • Harsh or toxic environments
  • Laboratories
  • Lakes
  • Landfills
  • Open channels
  • Pipes
  • Processing plants
  • Production facilities
  • Remote locations
  • Reservoirs
  • Rivers
  • Sewers
  • Stormwater systems
  • Streams
  • Underground locations
  • Water and wastewater treatment plants
  • Watersheds
  • Weirs
  • Wells
  • Wildlife refuges and habitats
What industries use automatic water samplers?

Water samplers are used in a variety of industries, such as the following:

  • Chemical
  • Environmental
  • Food and beverage
  • Industrial facilities with stormwater discharge
  • Manufacturing
  • Marine
  • Municipal
  • Pulp and paper
  • Wastewater treatment
  • Utilities
What do automatic water samplers help measure?

Water samples, collected by a water sampler, can be measured and analyzed for a variety of parameters, including the following:

  • Alkalinity
  • Ammonia
  • Biochemical oxygen demand
  • Bromide
  • Chemical oxygen demand
  • Chloride
  • Color
  • Conductivity
  • Dissolved metals, metalloids, and salts
  • Dissolved organics
  • Dissolved oxygen
  • Fecal contamination
  • Free chlorine residual
  • Heavy metals
  • Microorganisms
  • Nitrate
  • Odor
  • Orthophosphates
  • Oxygen-reduction potential (ORP)
  • Pesticides
  • pH
  • Pharmaceuticals
  • Presence of insects
  • Radon
  • Salts
  • Taste
  • Temperature
  • Total dissolved solids (TDS)
  • Total suspended solids (TSS)
  • Turbidity
  • Viruses and bacteria
How much tubing is needed between a water source and a water sampler?

The tubing from the water sampler’s pump tubing intake to the water source should be as short as possible to aid the downhill routing of the fluid. The tubing should not be allowed to coil.

To estimate how much tubing is needed between the water sampler and the water source, use the rise (vertical distance) and run (horizontal distance) to calculate the slope length (length of tubing required).

Note: A minimum of 25 feet in tubing length is recommended for a vacuum pump sampler.

Can the water sampler be positioned below the water source?

No. The water sampler should be positioned above the water source to prevent gravity from causing continued siphoning to flood the water sampler. 

What type of maintenance does a water sampler require?

The need for cleaning and maintenance varies depending on the sampler being used, as well as the fluid being sampled and tested. The following, however, are some general maintenance suggestions for all water samplers:

  • Routinely check that all tubing is clean and free of obstructions.
  • After analyzing the samples, clean the sample containers.
  • Routinely check that all tubing is free from cracks or splits.
  • Replace any worn parts.
  • Replace tubing to avoid algae or bacterial growth.
  • Clean any dirty parts.
  • Check that water sample volumes in the sample containers are correct. (A significant variance would require further investigation.)
  • Using the controller, ensure that all samples have been collected as programmed. (Missing samples would require further investigation.)
  • If a refrigerator is used, ensure that samples are kept at a temperature of 4 degrees Celsius.
  • If continuous sampling is desired, remove the filled sample containers, and replace them with clean, empty sample containers.

Refer to the specific water sampler’s instruction manual for detailed maintenance information.

Is there a way to be notified if an automatic water sampler does not collect a sample?

If a water sampler is used with a datalogger, the datalogger can be programmed to notify sampling personnel if a water sampler fails to collect a sample. The notification can be made through a variety of methods including an alarm, bell, whistle, light, etc. Additional notification options are available when a communications peripheral is used.

How large or heavy are automatic water samplers?

Water samplers come in a range of sizes and weights depending on the type of water sampler and which components are included. The following are some examples for illustrative purposes:

  • A compact portable sampler designed to fit in a small-sized manhole can weigh approximately 25 pounds, including the battery.
  • A portable sampler designed to fit in a standard-sized manhole can weigh approximately 40 pounds, including the battery.
  • A stationary sampler with a refrigerator can weigh from 150 to 250 pounds.
Should an ac power supply or a battery be used with a water sampler?

For a water sampler, it is recommended to use an ac power source whenever one is available. Using an ac power source eliminates the inconvenience of replacing or recharging depleted batteries. An ac power source can also deliver more power to a water sampling system.

To run a water sampler, does a backup battery need to be used with an ac power source?

Using an ac power source with a battery backup option is a reliable method to ensure smooth, continuous operation. In the event of ac power failure, the battery can supply the required power to continue the sampling program for the short term. 

If no ac power source is available, can just one external battery power a water sampler?

In a situation where a battery must be used, it is important to sustain power to the water sampler—especially when the battery begins losing a significant amount of charge. Sampling personnel need to manually replace depleted batteries with a ready supply of fully charged batteries.

The frequency with which the batteries need to be replaced may be reduced by using solar panels. Solar panels are only a practical option, however, if there is enough available, consistent solar radiation at the sampling site.

If it is difficult to replace the batteries, solar power is not a practical option, or the water sampling system’s power requirements are great, then a deep-cycle rechargeable battery may be a suitable option.

How can the external battery voltage of the water sampler be checked?

To check the external battery’s voltage, connect a metering device to the battery. Keep it connected for several seconds to allow the device to level out. If the voltage is below 12.3 Vdc, it may be necessary to recharge the battery.

Does replacing an external battery cause the water sampler program memory to be deleted?

Replacing a battery is a quick process that will not cause the sampler to lose its programmed settings and information. The control panel has an internal battery and a small amount of memory that will preserve the information while the battery is replaced.

If an external battery is replaced on an automatic water sampler, will the sampling program automatically resume?

With some sampler models, the automatic sampling program will automatically resume. With other models, it may be necessary to restart the system. For details on this topic, consult the instruction manual for the particular water sampler.

Does the internal battery in a water sampler controller ever need to be replaced?

How long the controller’s internal 3.6 Vdc battery lasts depends on how long it remains in disuse, how long it is in use, and the complexity of the running program. Typically, the internal battery should provide several years of continued service. 

Can a 10164-L Water Sampler Control Cable be used to interface Campbell Scientific dataloggers with ISCO water samplers?

Yes. We have developed programs for controlling devices and collecting data remotely. Program examples and datalogger wiring are provided in the instruction manual for the 10164-L. Contact an application engineer at Campbell Scientific for more information.

What might indicate that the internal battery of a water sampler is failing?

An internal battery may be failing if the charge is down to 2.9 Vdc. Another indication of internal battery failure is that entered programs are not stored in memory.  

What is the proper way to replace the internal battery of a water sampler?

When replacing an internal battery, ensure that the new battery is not automatically discharged. To prevent this, follow these steps:

  1. Either plug the sampler into an ac power source, or ensure that it has a fully charged external battery.
  2. Make sure the sampler is turned on.
  3. Remove the old internal battery.
  4. Insert the new internal battery.
How easy is it to program a water sampler?

Programming an automatic water sampler is as easy as viewing the prompts on the controller’s LCD screen and touching the keypad in response. Water sampler suppliers may provide online videos demonstrating how this is done. One such example, posted on YouTube, is “Programming Campbell Scientific Water Samplers.” Water sampler suppliers may also provide instruction manuals in various formats, such as on line, CD, DVD, or printed copy. 

Does ice have to be used with a portable water sampler?

It is optional to use ice in a portable water sampler. Deciding whether to use ice, and, if so, how much, depends on two things: the sampling requirements for keeping the sample chilled before analysis, and the potential for biological or chemical changes because of temperature changes.

What is the standard refrigerator temperature for a stationary water sampler?

The required holding temperature for many samples is 4°C (39°F). Consequently, refrigerators for water samplers are adjustable to maintain a 4°C temperature.

Should glass or plastic water sample containers be used?

The choice of material for sample containers depends on what is being sampled and how the elements will react with the container. For example, glass containers may be more suitable for the following:

  • Metals or petrochemicals
  • Oil and grease
  • Volatile organic compounds (VOCs) 
Do oil and grease coat water sampling equipment and contaminate subsequent samples?

If water samples contain oil or grease, Teflon-coated sampling equipment and glass sample containers should be used to prevent residue that can contaminate subsequent samples.  

What are the special needs for water samples with metals or petrochemicals?

When water samples contain metals or petrochemicals, the following should be used:

  • Glass chambers
  • Glass sample containers
  • A non-lead sinker on the end of the intake hose
  • Silicone discharge tubing
  • Teflon-lined intake tubing
How long can a water sample be held before it is analyzed?

The holding time is specified by the authority governing the water sampling process for the site. The holding time is the maximum amount of time a sample can be held before analysis and still be considered a valid sample. If a sample exceeds the holding time, it is considered suspect, and the sample collection may have to be repeated.

Typically, water samples have a maximum holding time that ranges anywhere from six hours to six months. Some attributes, however, require immediate analysis, such as the following:

  • Dissolved oxygen
  • pH
  • Sulfite
  • Temperature
  • Total residual chlorine
In water sampling, when are sinkers or strainers used?

A sinker is used alone to keep the sample line fully submerged in the water source. The use of a strainer is optional. A combination sinker/strainer is used to prevent the intake line from clogging with large solid particles or leaves. 

How is slope length calculated?

The slope length is calculated using the Pythagorean Theorem, where the vertical distance is the rise and the horizontal distance is the run: rise2 + run2 = slope length2.

Example: If a water sampler was placed at a vertical distance of 10 feet and a horizontal distance of 20 feet from a water source, the equation would be solved like this:

102 + 202 = slope length2

100 + 400 = slope length2

500 = slope length2

√500 = slope length

 ≈22.36 feet = slope length

In this example, the facility would need more than 22 feet of tubing to cover the distance from the water sampler to the water source.

Note: A minimum tubing length of 25 feet is recommended for a vacuum pump sampler. 

What should be done if the content of a water source to be sampled is unknown?

If water sampling at a particular site has not been conducted before and the facility is unaware of what is in the water source, the facility should collect a water sample and have it tested in a laboratory. This information can be used to select water sampling equipment that is appropriate for the application before beginning a sampling program.

What might cause a water sampler pump to not start? How can this be fixed?

Check to ensure that the voltage of the external battery is adequate. For water samplers with a large pump, the battery voltage should be greater than 12.3 Vdc. If the voltage is below 12.3 Vdc and a large pump is being used, recharge the battery to full charge. If the water sampler is a PVS-series sampler and ac power is available, keep the sampler plugged in.

If the pump continues to fail to start, follow these steps:

  1. Remove the bottom splash plate.
  2. Tap the pump with a rubber mallet while attempting to initiate a manual sample.
  3. Check the voltage at the pump. If the voltage is below 12.3 Vdc, check the wiring to ensure that it is making contact and that no corrosion is present. As necessary, tighten the contacts, replace any broken wires, and clean off the corrosion.
  4. Recheck the voltage at the pump. If the voltage reading is greater than 12.3 Vdc and the pump continues to fail starting, the pump is faulty and should be replaced or repaired if parts are available. Rebuild kits are available for some pumps. Contact an application engineer at Campbell Scientific for further assistance.
Why might a water sampler turn on but fail to collect a sample? How can this be fixed?

Try the following steps:

  1. Remove the intake hose from the intake volume control tube.
  2. Perform a manual sample.
  3. Check all air hose connections to ensure that there are no loose fittings or leaks.
  4. Check the meter chamber cover lid for proper connections. Ensure that everything is correctly installed and that the O-rings are in place.
  5. Verify that the pinch bar on the discharge tube is closing properly and not allowing vacuum or purge leakage.
  6. Check the solenoid valves on the pump to see if they are purging or vacuuming at the air tube connection of the metering chamber.
  7. If air is not purging and vacuuming from the tube at the metering chamber connection, remove the solenoid valves from the pump, and check for air pressure at the pump output port.
    • If air pressure is present at the pump output port, replace the solenoid valves with pn 27893.
    • If no air pressure is present at the pump output port, either rebuild the pump (if it is a large pump) with the rebuild kit pn 28620, or replace the pump (if it is a small pump).
Why might a water sampler controller not retain its programs?

It may be that the internal battery in the controller needs to be replaced. Remove the four screws from the front of the keypad, and check the voltage of the internal battery. The internal battery is a 3.6 Vdc battery. An indication that the internal battery may be failing is if the charge is down to 2.9 Vdc and if entered programs are not stored in memory. Replace the drained battery with a fresh one, but ensure that the sampler is plugged into a power source with the power on to keep the new internal battery from discharging. 

What might cause a row of black squares to appear on the LCD of a water sampler?

Several possible causes exist. Follow the steps below to check the battery voltage of the internal battery in the controller:

  1. Loosen the four screws holding the keypad lid on just enough so that the lid can be lifted off.
  2. Without disconnecting the cable connected to the LCD board, check the internal battery voltage for dc voltage greater than 2.9 Vdc.
  3. If the voltage is 2.9 Vdc or less, replace the battery with pn 13519, reattach the lid, tighten the four screws, and restart the sampler.
  4. If the black squares are still present on the display, check the voltage coming from the power supply to the sampler. For readings below 12.5 Vdc, contact an application engineer at Campbell Scientific for additional information and help.
What does it mean if the water sampler LCD displays “fault shutdown sample abandoned”?

This message indicates that the water sampler was unable to pull a successful sample. The sampler will make another attempt at the next scheduled event. If the second attempt is also unsuccessful, the LCD will display full fault shutdown with a time stamp and date. The sampler will not sample again until the error is corrected and the Reset button has been pressed twice.

Some possible causes and their remedies are listed below:

  • The intake hose may be clogged, perhaps because of a weight or strainer that is stuck in a stream bed or covered with debris. Blow air through the intake tube until it is clear of obstructions.
  • There may be a vacuum leak. An O-ring may be missing, or there may be loose connections. Check all the blue air tubing for leaks at the meter chamber, pump solenoid valves, and meter chamber assembly.
  • No water may be present at the intake sample hose. Check the position of the end of the hose at the intake point.
What does it mean if the water sampler LCD displays “fault shutdown power failure”?

This message indicates that at some point the power supply was reduced enough that the water sampler did not have enough power to draw a sample, which caused a shutdown of the system. The system will not operate until the Restart button is pushed twice.

Losing ac power without an integral backup battery will cause this type of failure. After power is resumed, pressing the Restart button twice will reset the water sampler to its previous settings.

Resources and Links

About Water Samplers

Campbell Scientific offers both portable and stationary automatic water samplers for storm water, waste water, or other water-quality applications. These samplers use external vacuum pumps to draw water through intake tubing, instead of the traditional peristaltic pumps that induce flow by squeezing flexible tubing. Advantages of the vacuum pump method include faster sampling rates, better vertical lifts, longer sampling distances, and less maintenance. Because the vacuum method disturbs the water samples less, they better represent the original water solution, especially if the solution has high concentrations of suspended solids.

The automatic water samplers offered by Campbell Scientific include a controller that can accept a pulse input (e.g., rain gage), a 4 to 20 mA signal (e.g. flow meter), or initiate a sample on a timed basis. The samplers can also be interfaced with our dataloggers. Our dataloggers can measure nearly any turbidity, water level, or hydrometeorological sensor, as well as control the sampler based on time, event, or measured conditions.

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