CS655

12 cm Soil Moisture and Temperature Sensor

CS655

Orderable

12 cm Soil Moisture and Temperature Sensor

Pricing

Configuration

w/3m per Sensor -PF w/ Ferrules on WiresCS655-3mPart Number: 45054-3m
(-50 to +70C) w/5m (17ft) per Sensor -PF w/Ferrules on WiresCS655-5mPart Number: 45054-5m
(-50 to +70C) w/10m (33ft) per Sensor -PF w/Ferrules on WiresCS655-10mPart Number: 45054-10m
(-50 to +70C) w/20m (66ft) per Sensor -PF w/Ferrules on WiresCS655-20mPart Number: 45054-20m
w/30m per Sensor -PF w/ Ferrules on WiresCS655-30mPart Number: 45054-30m

Qty

Select a configuration to add to your quote

Model:: CS655
Item Number:: 45054
Warranty:: 1 year

Overview

The CS655 is a multiparameter smart sensor that uses innovative techniques to monitor soil volumetric-water content, bulk electrical conductivity, and temperature. It outputs an SDI-12 signal that many of our data loggers can measure. It has shorter rods than the CS650, for use in problem soils.

Note: The cable termination options for this sensor are not suitable for use with an ET107 station. For this type of station, use the CS655-LC sensor instead, which has a suitable cable connector.

Key Advantages

Innovative
More accurate in soils with high bulk EC

Technical Description

The CS655 consists of two 12-cm-long stainless steel rods connected to a printed circuit board. The circuit board is encapsulated in epoxy and a shielded cable is attached to the circuit board for data logger connection.

The CS655 measures propagation time, signal attenuation, and temperature. Dielectric permittivity, volumetric water content, and bulk electrical conductivity are then derived from these raw values.

Measured signal attenuation is used to correct for the loss effect on reflection detection and thus propagation time measurement. This loss-effect correction allows accurate water content measurements in soils with bulk EC ≤8 dS m^-1 without performing a soil-specific calibration.

Soil bulk electrical conductivity is also calculated from the attenuation measurement. A thermistor in thermal contact with a probe rod near the epoxy surface measures temperature. Horizontal installation of the sensor provides accurate soil temperature measurement at the same depth as the water content. Temperature measurement in other orientations will be that of the region near the rod entrance into the epoxy body.

Benefits

Larger sample volume reduces error
Measurement corrected for effects of soil texture and electrical conductivity
Estimates soil-water content for a wide range of mineral soils
Versatile sensor—measures dielectric permittivity, bulk electrical conductivity (EC), and soil temperature

Specifications

Measurements Made: Soil electrical conductivity (EC), relative dielectric permittivity, volumetric water content (VWC), soil temperature
Required Equipment: Measurement system
Soil Suitability: Short rods are easy to install in hard soil. Suitable for soils with higher electrical conductivity.
Rods: Not replaceable
Sensors: Not interchangeable
Sensing Volume: 3600 cm³
(~7.5 cm radius around each probe rod and 4.5 cm beyond the end of the rods)
Electromagnetic: CE compliant
(Meets EN61326 requirements for protection against electrostatic discharge and surge.)
Operating Temperature Range: -50° to +70°C
Sensor Output: SDI-12; serial RS-232
Warm-up Time: 3 s
Measurement Time: 3 ms to measure; 600 ms to complete SDI-12 command
Power Supply Requirements: 6 to 18 Vdc
(Must be able to supply 45 mA @ 12 Vdc.)
Maximum Cable Length: 610 m
(2000 ft) combined length for up to 25 sensors connected to the same data logger control port
Rod Spacing: 32 mm
(1.3 in.)
Ingress Protection Rating: IP68
Rod Diameter: 3.2 mm
(0.13 in.)
Rod Length: 120 mm
(4.7 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)
Probe Weight: 240 g
(8.5 oz) without cable

Current Drain

Active (3 ms): 45 mA typical
(@ 12 Vdc)
80 mA
(@ 6 Vdc)
35 mA
(@ 18 Vdc)
Quiescent: 135 µA typical
(@ 12 Vdc)

Electrical Conductivity

Range for Solution EC: 0 to 8 dS/m
Range for Bulk EC: 0 to 8 dS/m
Accuracy: ±(5% of reading + 0.05 dS/m)
Precision: 0.5% of BEC

Relative Dielectric Permittivity

Range: 1 to 81
Accuracy: ±(3% of reading + 0.8)
from 1 to 40 for solution EC ≤ 8 dS/m
±2
(from 40 to 81 for solution EC ≤ 2.8 dS/m)
Precision: < 0.02

Volumetric Water Content

Range: 0 to 100%
(with M4 command)
Water Content Accuracy: ±1%
(with soil-specific calibration) where solution EC < 3 dS/m
±3%
(typical with factory VWC model) where solution EC < 10 dS/m
Precision: < 0.05%

Soil Temperature

Range: -50° to +70°C
Resolution: 0.001°C
Accuracy: ±0.1°C
(for typical soil temperatures [0 to 40°C] when probe body is buried in soil)
±0.5°C
(for full temperature range)
Precision: ±0.02°C

Accessories

(6)

Common Accessories

(5)

Other Accessories

(5)

Similar Products

(6)

Compatibility

RF Considerations

External RF Sources

External RF sources can affect the probe’s operation. Therefore, the probe should be located away from significant sources of RF such as ac power lines and motors.

Interprobe Interference

Multiple CS655 probes can be installed within 4 inches of each other when using the standard data logger SDI-12 “M” command. The SDI-12 “M” command allows only one probe to be enabled at a time.

Optional Installation Tool

CS650G Rod Insertion Guide 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 was not used. It makes pilot holes into which the rods of the sensors can then be inserted.