Probe care — you cannot calibrate screened pH or NPK

TerraProbe does not have a pH electrode. Screened pH, nitrogen, phosphorus and potassium are calculated from the conductivity reading. You cannot calibrate them with buffer solutions, and doing so would not make them laboratory results.

WHAT YOU CAN DO
Keep the measured sensors honest by technique, not by bottles.

1. Rinse the five pins with clean water between paddocks so you are not carrying salts from one sample to the next.

2. Insert all five pins fully and vertically. Wait until conductivity settles — usually under ten seconds — then save. Moisture, EC and temperature are the measured values; everything else on the screen follows EC.

3. Sample at a consistent depth and moisture class if you want visits to compare.

4. Store the probe clean and dry. There is no seasonal pH calibration step, because there is nothing independent to calibrate.

If a reading looks wrong, take another at the same point after a rinse. If moisture, EC and temperature repeat, the screened values will too — they are the same signal. Confirm chemistry with an accredited laboratory when a decision needs it.

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Probe care — you cannot calibrate screened pH or NPK

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