The only way to thoroughly check a WATERMARK sensor is to remove it, soak it in water, and then hang it out to air dry.
- With a sensor submerged in water, your meter reading should be from 0 to 5. If the sensor passes this test, go on to step B.
- Let the sensor air dry for 30 to 48 hours. Depending on ambient temperature, humidity and air movement, you should see the reading go right up from zero to 150+
- Put the sensor back in water. The reading should return to below 5 within 2 minutes. If the sensor passes these tests, it is O.K.
If the sensor has been installed on the end of PVC pipe, you can do a quick check on a sensor by pouring water down the pipe. The sensor should drop to below 5 within a few minutes.