DANOPLUS Digital ORP Meter with Automatic Calibration & ORP Buffer Powder, -1200~1200mV High Accuracy ORP Tester for Testing Water

Q: Does the unit need to be calibrated before first use? Or is it calibrated out of the box.

Yes, the meter is calibrated before factory, we suggest to calibrate the meter again with the buffer powder after long-term use.

Q: Instructions say to calibrate to 263mv but the qrp buffer power packet says 256mv? small difference but why?

Hello, 256mv solution is a well-configured solution that does not affect the calibration. Calibrating the reading to 265mv while using 256mv ORP standard solution to calibrate will be fine. If there is 263mv, it can also be used for calibration.

Q: Can I know Ozone quantity in water with this instrument??

This meter will only measure ORP. It measures the oxidative reduction potential of a liquid. It measures neither ozone or Ph, but does a superb job for what it was intended.

Q: Is this supposed to be swished around,, or positioned steady?

Hi, it is static measurement. But please stir the probe gently to get rid of the air bubbles first when dip it into the solution to be tested and then keep it steady to get a stable reading.