GroLine Waterproof pH Tester is a high quality pH 4.01 calibration buffer that is NIST traceable and supplied with a Certificate of Analysis. Hanna calibration buffers have the lot number and expiration date clearly marked on the label and are air tight with a tamper-proof seal to ensure the quality of the solution. Hanna's line of technical calibration buffers have been specially formulated to have an expiration of 5 years from the date of manufacture for an unopened bottle.
- Supplied with Certificate of Analysis
- Accuracy of +/- 0.02 pH @ 25°C
- Temperature chart of the actual pH value at various temperatures printed on each bottle