PH Buffer 4 & 7

PH buffers are solutions of a known and fixed PH which are used to calibrate meters and should be done on a regular basis to ensure ongoing accuracy from the meter. Pour out a small amount to use for calibration and then discard solution when finished, do not pour back into container. Use PH buffer 7 to calibrate meter to neutral and then use PH buffer 4 to calibrate the correct acidic level for meter.