The CS526 isolated pH probe makes reliable, accurate pH measurements in aqueous solutions. It can be submersed or inserted into tanks, pipelines, and open channels. This probe has a serial, TTL output that represents a 2 to 12 pH range.Read More
The CS526 uses SENTRON’s high-tech, ion sensitive field effect transistor (ISFET) semiconductor as its pH-sensitive element, and includes a silver/silver chloride– potassium chloride reference system. The CS526’s design allows it to be suitable for a variety of liquid pH-monitoring applications. The electronics are safely embedded in a durable PEEK body. Elimination of the glass bulb removes the possibility of broken glass, making the CS526 more rugged and safer to use.
Note: Campbell Scientific warranty does not cover a clogged reference diaphragm or improperly cleaned or maintained ISFET chip. (See the Maintenance section in the instruction manual for more information.)
This sensor requires the 5 V output on the data logger to be powered..
|pH Range||2 to 12|
|Power Requirements||5 Vdc|
|Current Consumption||15 mA (maximum)|
|Accuracy||±0.2 pH (over 10° to 40°C)|
|Operating Temperature Range||10° to 40°C|
|24 h Drift||< 0.15 pH (after 15 min. soak in pH 7 at 25°C)|
|Allowed Water Pressure||0 to 700 kPa (0 to 101.5 psi)|
|Cable Type||Three-twisted pair, 24 AWG cable with Santoprene jacket|
|Sensor Material||Polyetheretherketone (PEEK)|
|Maximum Cable Length||100 m (328 ft)|
|Diameter||16 mm (0.63 in.)|
|Length||102 mm (4 in.)|
|Weight||318 g (11.2 oz) with 3.05 m (10 ft) cable|
Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.
Number of FAQs related to CS526-L: 15
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The source and the drain are two of the three electrodes contained within the ISFET chip, and they behave in much the same way. The third electrode in the ISFET chip, the gate, has an electrical field that influences the current that flows between the source and the drain. The electrical potential in the ISFET pH sensor is measured between the reference electrode and the source.
An ISFET chip pH sensor has three main components:
In an ISFET chip pH sensor, the chemical coating on the gate electrode can vary depending on the model and manufacturer of the pH sensor. Depending on which chemical coating is used and what elements are present in the sample solution, there may be some ion interference.
Cleaning and/or calibration may be required when the measurements are scattered, drifting occurs, or there is physical evidence of fouling. Measurements for pH must be monitored regularly to check for scattering. However, just because the results are scattered does not necessarily indicate the need for an adjustment. For example, there may be a change in the water source that causes the scattering. As a sensor ages, however, the scattering of the measured values tends to increase.
To check the performance of a pH sensor, use it to measure a buffer solution in the correct range. If the value returned is within the specified range, the sensor does not need to be calibrated.
Most Campbell Scientific sensors are available as an –L, which indicates a user-specified cable length. If a sensor is listed as an –LX model (where “X” is some other character), that sensor’s cable has a user-specified length, but it terminates with a specific connector for a unique system:
If a sensor does not have an –L or other –LX designation after the main model number, the sensor has a set cable length. The cable length is listed at the end of the Description field in the product’s Ordering information. For example, the 034B-ET model has a description of “Met One Wind Set for ET Station, 67 inch Cable.” Products with a set cable length terminate, as a default, with pigtails.
If a cable terminates with a special connector for a unique system, the end of the model number designates which system. For example, the 034B-ET model designates the sensor as a 034B for an ET107 system.
Not every sensor has different cable termination options. The options available for a particular sensor can be checked by looking in two places in the Ordering information area of the sensor product page:
If a sensor is offered in an –ET, –ETM, –LC, –LQ, or –QD version, that option’s availability is reflected in the sensor model number. For example, the 034B is offered as the 034B-ET, 034B-ETM, 034B-LC, 034B-LQ, and 034B-QD.
All of the other cable termination options, if available, are listed on the Ordering information area of the sensor product page under “Cable Termination Options.” For example, the 034B-L Wind Set is offered with the –CWS, –PT, and –PW options, as shown in the Ordering information area of the 034B-L product page.
Note: As newer products are added to our inventory, typically, we will list multiple cable termination options under a single sensor model rather than creating multiple model numbers. For example, the HC2S3-L has a –C cable termination option for connecting it to a CS110 instead of offering an HC2S3-LC model.
PolyEtherEtherKetone (PEEK) is a plastic material that has very good thermal stability and chemical resistance properties. This material was chosen for use in the manufacture of the CS526-L because of its natural resistance to organic acids (acetic, carbonic, citric, tartaric, etc.) and its hydrolysis resistance to fresh and saltwater.
Many Campbell Scientific sensors are available with different cable termination options. These options include the following:
Note: The availability of cable termination options varies by sensor. For example, sensors may have none, two, or several options to choose from. If a desired option is not listed for a specific sensor, contact Campbell Scientific for assistance.
The CR300 and CR310 dataloggers do not support TTL logic, which is what the CS526-L sensor uses. A TTL to RS-232 converter (supplied by the user) could be used, however.
The recommended calibration method listed in a specific pH sensor’s instruction manual should be followed to guarantee the best results. Calibration must be performed correctly to ensure accurate and repeatable measurements. Before performing calibration, the pH sensor should be cleaned.
Calibration is commonly done using a known-value pH solution called a buffer. The buffer solution is formulated to resist pH changes caused by external contaminants. However, the pH of the buffer solution changes as the temperature changes. To compensate for this, manufacturers list the pH of the buffer solution at various temperatures on the buffer solution’s bottle so that the correct value for calibration is selected.
The most common calibration method is a two-point calibration using two buffer solutions. Each buffer solution has known and accurate pH values at different temperatures. The buffers used should be based on the normal measurement range that the pH sensor operates in for the application. One buffer solution should have a 7.0 pH. The second buffer solution should have a pH that is near the expected pH value of the sample solution.