V1.2
TBSLWS1 SDI-12 Leaf Wetness Sensor
The default measurement unit for board temperature is degree Celsius, however using an extended SDI-12
command, the result can be changed to Fahrenheit
Extended SDI-12 commands:
aXCA! Air calibration factory calibrated
aXCW! Water calibration factory calibrated
The leaf wetness sensor is factory calibrated and can be installed right out of the box. Refer to chapter 4 for
details.
aXCT,stt.tt! temperature calibration factory calibrated
where s: sign
where tt.tt: ambient temperature measured with a reference thermometer
The temperature calibration is carried out in production; in case of a re-calibration, allow the sensor half an hour
to settle to room temperature
aXSTUu! set temperature unit; u= C for °C; u=F for °F
aXGTU! query temperature unit
Use the above command to configure the temperature unit; [°C] is the default setting
Measurement range: 0 to 100%
Measurement principle: capacitive measurement, PLL
Measurement response: 1 sec
SDI-12 Standard V1.3
6 - 16V supply voltage
Operating Temperature Range: - 40°C … + 80°C
Current consumption: active 8mA (for 1 second); idle 30µA
Standard cable length: 3m; any other length upon requirement
The TBSLWS1 comes factory calibrated and does not need any user calibration.
The TBSLWS1 is air / water calibrated. For air calibration, the dry sensor is placed in a way that its surface is not
touched by any object. Then issue the air calibration command. For water calibration, the complete sensor surface
is submerged in water and then the calibration command is issued.
If a higher sensitivity is required, the water calibration can be carried out with the sensor surface not completely
submerged in water, e.g. just half of the surface dipped into water when calibrating.
