WT-HR Water Height

Data Logger

The WT-HR is a Three Channel, High Resolution (12 bit), Water Height and Dual Temperature Datalogger fitted with a water height probe. Water height probes are available for:

A temperature sensor is located at the bottom of the water probe and another is mounted in the logger so both water and air temperatures can be logged.

Photos and Application notes

Compensating for Temperature Coefficients

The WT-HR water height probe has a small negative temperature coefficient with respect to water temperature. If the probe is sitting in 1 meter of water and experiences a water temperature increase of 1°C, the logger will report a water height decrease of 0.65mm. If you log water temperature, the Omnilog software can compensate the logged water height value to correct the small negative temperature coefficient of the probe.

In addition to this, the logger has a small positive temperature coefficient with respect to air temperature. If a probe is sitting at 0mm of water and experiences an air temperature increase of 1°C, the logger will report a water height increase of 0.5mm. If you log air temperature, the Omnilog software can compensate the logged water height value to correct the small positive temperature coefficient of the logger.

Logging both water and air temperature, as well as water height, decreases the number of samples you can store in the logger. If the air and water temperature are going to be reasonably constant, (eg. down a well) you can log water height only. You can also log water height only if your required accuracy is greater than 10mm. The water temperature has a larger coefficient than the air temperature, so if you can only afford to log one temperature it is recommended that you log water temperature.
If you attempt to start the logger without selecting both water and logger temperatures a warning message will appear.