CS506-L Fuel Moisture Sensor
Remote Measurements
Monitors forest-fire factor; ideal for use with RAWS
weather applications water applications energy applications gas flux & turbulence applications infrastructure applications soil applications

Overview

The CS506 is a fuel moisture sensor that measures the moisture content of the 26601 10-hour fuel moisture stick. The 26601 emulates the moisture content of similarly sized twigs on the forest floor. The CS506/26601 combination is used to assess forest fire fuel and is often incorporated in our prewired or custom fire-weather stations.

Note: The image shows a CS506 fuel moisture sensor attached to a 26601 fuel moisture stick. The 26601 is purchased separately.

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Benefits and Features

  • Compatible with most Campbell Scientific dataloggers
  • Companion product to CS205/107 fuel temperature sensor; can be mounted on the same stake
  • Can automatically monitor changing fuel conditions without having to visit the measurement site
  • Compatible telemetry options include spread spectrum radios, narrow-band radios, cellular phones, and satellite transmitters

Images

CS506 fuel moisture sensor attached to a 26601 fuel moisture stick (sold separately)
CS506 fuel moisture sensor attached to a 26601 fuel moisture stick (sold separately)
CS506 fuel moisture sensor attached to a 26601 fuel moisture stick (sold separately)
26817 mounting stake with a CS506, 26601, CS205, and 107 (items sold separately)

Similar Products

Detailed Description

The CS506 reports the status of small-diameter (10-hour) forest fire fuels as percent moisture by weight (1%=1 g water/100 g dry fuel). It consists of an epoxy-encapsulated electronics package that uses time-domain reflectometry (TDR) technology to measure the moisture content of the 26601 10-hour Fuel Moisture Stick. The sensor produces a ±0.7 Vdc square-wave frequency that is read using an analog or pulse channel on a Campbell Scientific datalogger. The datalogger then converts the frequency measurement to percent fuel moisture via a quadratic calibration.

Specifications

Operating Range 0 to 70% moisture content
Power Supply 5 to 18 Vdc
Enable Voltage
  • off at 0 Vdc (< 1 Vdc)
  • on at 5 Vdc (> 4 Vdc; maximum 18 Vdc)
Current Consumption
  • 65 mA (active)
  • 45 μA (quiescent)
Output Signal ±0.7 Vdc square wave (with an output frequency of approximately 31 to 58 kHz)
Dimensions 10.16 x 6.35 x 1.91 cm (4 x 2.5 x 0.75 in.)
Weight < 0.5 kg (< 1 lb)

Fuel Moisture Accuracy

0 to 10% Range
  • ±1.25% (worst case)
  • ±0.74% (RMS error)
10 to 20% Range
  • ±2% (worst case)
  • ±0.9% (RMS error)
20 to 30% Range
  • ±3.4% (worst case)
  • ±1.94% (RMS error)
30 to 50% Range
  • ±4.11% (worst case)
  • ±2.27% (RMS error)

Compatibility

Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.

Dataloggers

Product Compatible Note
21X (retired)
CR10 (retired)
CR1000
CR10X (retired)
CR200X (retired)
CR206X (retired)
CR211X (retired)
CR216X (retired)
CR23X (retired)
CR295X (retired)
CR300
CR3000
CR310
CR500 (retired)
CR5000 (retired)
CR510 (retired)
CR6
CR800
CR850
CR9000 (retired)
CR9000X

Additional Compatibility Information

Fuel Temperature

The CS506 is typically measured alongside the CS205/107, which measures the fuel temperature.

Mounting

The 26817 Mounting Stake is often used to mount the CS506/26601 with the CS205/107. This stake places the probes twelve inches above the forest floor. Because the probes are mounted parallel to each other, shadowing is minimized. Cable ties are included for securing the cables to the side of the stake.

Datalogger Considerations

Programming

The CS506 produces a ±0.7-Vdc square-wave frequency that is read using an analog or pulse channel on a Campbell Scientific datalogger. The datalogger then converts the frequency measurement to percent fuel moisture via a quadratic calibration.


Frequently Asked Questions

Number of FAQs related to CS506-L: 6

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    • The CS506-L Fuel Moisture Sensor uses a 26601 10-Hour Fuel Moisture Stick.
    • The 107 Temperature Probe uses a CS205 10-Hour Fuel Temperature Stick.

    Both of these dowels can be easily replaced in the field with a Phillips screwdriver and an adjustable wrench.

  1. For descriptions and illustrations (with part numbers) of the various instruments used in measuring fuel temperature and moisture, see the "Remote Measurements" brochure.

  2. Both the 26601 10-Hour Fuel Moisture Stick (used with the CS506-L) and the CS205 10-Hour Fuel Temperature Stick (used with the 107-L) can be easily replaced in the field with a Phillips screwdriver and an adjustable wrench.

    The dowels should be replaced each spring; more frequent replacements may be required in some environments. The more wet/dry cycles the dowels experience, the more frequently they will need to be replaced.

  3. 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:

    • An –LC model has a user-specified cable length for connection to an ET107, CS110, or retired Metdata1.
    • An –LQ model has a user-specified cable length for connection to a RAWS-P weather station.

    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.

    • –ET models terminate with the connector for an ET107 weather station.
    • –ETM models terminate with the connector for an ET107 weather station, but they also include a special system mounting, which is often convenient when purchasing a replacement part.
    • –QD models terminate with the connector for a RAWS-F Quick Deployment Station.
    • –PW models terminate with the connector for a PWENC or pre-wired system.
  4. 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:

    • Model number
    • Cable Termination Options list

    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. 

  5. Many Campbell Scientific sensors are available with different cable termination options. These options include the following:

    • The –PT (–PT w/Tinned Wires) option is the default option and does not display on the product line as the other options do. The cable terminates in pigtails that connect directly to a datalogger.
    • In the –C (–C w/ET/CS110 Connector) option, the cable terminates in a connector that attaches to a CS110 Electric Field Meter or an ET-series weather station.
    • In the –CWS (–CWS w/CWS900 Connector) option, the cable terminates in a connector that attaches to a CWS900-series interface. Connection to a CWS900-series interface allows the sensor to be used in a wireless sensor network.
    • In the –PW (–PW w/Pre-Wire Connector) option, the cable terminates in a connector that attaches to a prewired enclosure.
    • In the –RQ (–RQ w/RAWS Connector) option, the cable terminates in a connector that attaches to a RAWS-P Permanent Remote Automated Weather Station.

    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.

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