Overview
Due to the type of cable being used, the measurement range of the standard thermistor temperature probe is from -30°C to 100°C. Accuracy of these probes is ±0.1°C making them ideally suited to measuring temperature profiles in water.
The 6508 very low power, precision SDI-12 temperature sensor is used for measuring temperatures between -20°C and 70°C. It is submersible, stable, 24-bit digital sensor ideal for measuring water, soil and ambient temperatures.
SDI-12 Version: V1.3, SDI-12 Command support: a! acknowledge, aI! return identification, aAb! change address, aM! aMC! start measurement and aD! return measurement data.
The 6535 linear temperature probe is used for measuring temperatures between -17.8°C and 100°C. It outputs a DC voltage, the value of which is directly proportional to temperature.
The linear temperature probes integrate the LM34 precision Fahrenheit temperature sensor whose output voltage is linearly proportional to the Fahrenheit temperature. The probe operates from 5V to 30V, does not require any external calibration or trimming to provide typical accuracies of ±11/2°F(°C) over a full -40°F (-40°C) to 240°F(115.5°C) temperature range. Due to the type of cable being used, the measurement range is ~-17.8°C to 100°C.
The LM34 draws only 75µA from its supply so it has very low self-heating; furthermore it has low output impedance and linear output making interfacing of this probe very easy.
Specifications

6507
Physical specifications
- Material: Stainless steel tube epoxy sealed
- Size: Dia 6.40mm x 50mm long, different tube lengths available on request
- Weight: 350 grams
Electrical specifications
- Temperature Range: -30° to +100°C
- Temperature Accuracy: ±0.1°C
- Operating voltage: 5 VDC, from logge
- Typical current consumption: 0.5mA at 5VDC
- Outputs: 1 analog 0-2.55VDC
- Cable: 10m or 20m 2 core cable shielded. Other cable lengths available on request
6508
Physical specifications
- Material: Stainless steel tube, PVC, Polyurethane
- Size: Dia 12.7 mm x 145mm long
- Weight: 220 grams with 10m cable
Electrical specifications
- Temperature Range: -20° to +70°C
- Temperature Accuracy : -5° to +50°C: ±0.1°C
- Temperature Accuracy: -20° to +70°C: ±0.5°C
- Resolution: 0.01°C
- Response Time:: 22s to 63.2% of a step change
- Operating voltage: 6 to 16 VDC
- Typical Sleep current: 340µA
- Active current: Less than 4mA while responding to an SDI-12 command
- Outputs: 1 analog 0-2120mVDC (18mV/°C)
- Cable: 10m Other cable lengths available on request (up to 60m as per SDI-12 standard)
6535
Physical specifications
- Material: Stainless steel tube epoxy sealed
- Size: Dia 8 mm x 100mm long, different tube lengths available on request
- Weight: 350 grams
Electrical specifications
- Temperature Range: -17.8° to +100°C
- Temperature Accuracy: ±1.5°C
- Operating voltage: 5 VDC, from logger
- Typical current consumption: 150µA at 5VDC
- Outputs: 1 analog 0-2120mVDC (18mV/°C)
- Cable: 10m or 20m 4 core cable shielded. Other cable length available on request