The Comboinstruments Soil pH/ Humidity Meter 30cm works with all substrates. With this size, you can get more profound and accurate measurements. You can measure the coconut fiber, the stonewool, the perlite, the vermiculite, soil, and even clay pebbles.
The range of pH measurement: 3 ÷ 8
Humidity measurement range: 1 ÷ 8
Range of error 0.1 – 0.5
It does not require calibration
It does not require a battery
Maximum diameter: ø51mm