RETIRED ›
This product is no longer available.
CS625 Water Content Reflectometer for CR200(X)-Series and CR300-Series
Services Available
Repair Yes
Calibration No
Free Support Yes

Overview

The CS625 measures the volumetric water content from 0% to saturation. It is similar to our CS616 but is designed specifically for CR200(X) and CR300-series dataloggers. This reflectometer has a 0 to 3.3 V square wave frequency output that our CR300-series and CR200(X)-series dataloggers can measure.

Read More

Benefits and Features

  • High accuracy and high precision
  • Fast response time
  • Designed for long-term unattended water content monitoring
  • Probe rods can be inserted from the surface or buried at any orientation to the surface.

Images

Detailed Description

The CS625 consists of two 30-cm-long stainless steel rods connected to a printed circuit board. The circuit board is encapsulated in epoxy, and a shielded four-conductor cable is connected to the circuit board to supply power, enable probe, and monitor the output.

The CS625 measures the volumetric water content of porous media (such as soil) using the time-domain  measurement method; a reflectometer (cable tester) such as the TDR100 is not required. This method consists of the CS625 generating an electromagnetic pulse. The elapsed travel time and pulse reflection are then measured and used to calculate soil volumetric water content.

Response Characteristics

The signal propagating along the parallel rods of the CS625 is attenuated by free ions in the soil solution and conductive constituents of the soil mineral fraction. In most applications, the attenuation is not enough to affect the CS625 response to changing water content, and the response is well described by the standard calibration. However, in soil with relatively high soil electrical conductivity levels, compacted soils, or soils with high clay content, the calibration should be adjusted for the specific medium. Guidance for making these adjustments is provided in the operating manual.

Specifications

Measurements Made Volumetric water content of porous media (such as soil)
Water Content Accuracy ±2.5% VWC (using standard calibration with bulk EC of ≤ 0.5 dS m-1, bulk density of ≤ 1.55 g cm-3, and measurement range of 0% to 50% VWC)
Required Equipment Measurement system
Soil Suitability Long rods and lower frequency are well-suited for soft soil with low electrical conductivity (< 2 dS/m).
Rods Not replaceable
Sensors Not interchangeable
Operating Temperature Range 0° to 70°C
Probe-to-Probe Variability ±0.5% VWC in dry soil, ±1.5% VWC in typical saturated soil
Precision 0.1% VWC
Resolution 0.1% VWC
Output 0 to 3.3 V square wave (with frequency dependent on water content)
Current Drain
  • 65 mA @ 12 Vdc (when enabled)
  • 45 μA (quiescent typical)
Power Supply Voltage 5 Vdc minimum; 18 Vdc maximum
Enable Voltage 4 Vdc minimum; 18 Vdc maximum
Electromagnetic CE compliant (Meets EN61326 requirements for protection against electrostatic discharge.)
Rod Spacing 32 mm (1.3 in.)
Rod Diameter 3.2 mm (0.13 in.)
Rod Length 300 mm (11.8 in.)
Probe Head Dimensions 85 x 63 x 18 mm (3.3 x 2.5 x 0.7 in.)
Cable Weight 35 g per m (0.38 oz per ft)
Weight 280 g (9.9 oz) without cable

Compatibility

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

Data Loggers

Product Compatible Note
CR1000 (retired)
CR200X (retired)
CR206X (retired)
CR211X (retired)
CR216X (retired)
CR295X (retired)
CR300
CR3000 (retired)
CR310
CR5000 (retired)
CR800 (retired)
CR850 (retired)
CR9000X (retired)

Additional Compatibility Information

RF Considerations

The RF emissions are below FCC and EU limits as specified in EN61326 if the CS625 is enabled less than 0.6 ms, and measurements are made less frequently than once a second. External RF sources can also affect the CS625 operation. Consequently, the CS625 should be located away from significant sources of RF such as ac power lines and motors.

Installation Tool

The CS650G makes inserting soil-water sensors easier in dense or rocky soils. This tool can be hammered into the soil with force that might damage the sensor if the CS650G were not used. It makes pilot holes into which the rods of the sensors can then be inserted. It replaces both the 14383 and 14384.

Data Logger Considerations

Each CS625 requires a single-ended input channel. A control port is used to enable one or more probes.

Note: A maximum of four CS625 probes can be measured by one CR200(X) datalogger. Valid channel options are analog channels 1 through 4.


Frequently Asked Questions

Number of FAQs related to CS625: 34

Expand AllCollapse All

  1. Yes, as long as the data logger can detect a 0 to 3300 mV square wave over a frequency range of 29 to 67 kHz.

  2. Yes. The rugged design of the CS616/CS625 protects the probe electronics from water under these conditions. Many CS616/CS625 reflectometers have been working reliably in very wet conditions for more than ten years.

  3. Cutting down rods should only be done at the user’s own risk. Doing so will cause the probe to need recalibration. Campbell Scientific does not provide calibrations for shorter rod lengths for the CS616 or the CS625.

    With shorter rods, the probe will work, but there will be some reduction in accuracy because the length of the rod in the soil contributes a smaller proportion to the total transit time. However, probes with shorter rods will work in more saline soils.

  4. If a soil-specific calibration is performed, the CS616/CS625 may be used in soil with a maximum bulk electrical conductivity of 5 dS/m.

  5. If the electrical conductivity within the waste is less than 5 dS/m and there is good contact between the probe rods and the waste, the CS616/CS625 should respond predictably to changes in water content. The heterogeneous nature and changing bulk density of solid waste, however, make calibration difficult.

  6. Some customers have tried to use the CS616 or CS625 to measure the moisture content within a tree, but the calibration proved to be problematic. Campbell Scientific cannot provide any specific guidance for this application.

  7. Fine roots do not significantly affect the CS616/CS625 reading.

  8. The CS616/CS625 can measure volumetric water content over the entire range from completely dry to saturation. A soil-specific calibration will improve accuracy, especially in very dry soil.

  9. Yes. For program examples and guidance on using a multiplexer with one of these reflectometers, see the CS616 and CS625 instruction manual.

Privacy Policy Update

We've updated our privacy policy.  Learn More

Cookie Consent

Update your cookie preferences.  Update Cookie Preferences