GroLine pH 4.01 Calibration Solution - 500ml

pH meters should be calibrated frequently (every 1-4 weeks, depending on use). Two-point calibration (using both 4.0 & 7.0 buffers) ensures the most accurate calibration possible. Do not reuse calibration solution, as once it has been used, it is no longer sterile and may result in improper readings. Pour a small amount into a shot glass and discard after use (unless your using using the sachets). Suitable for all makes and models of pH pens and meters.