Hanna pH 3.00 Technical Calibration Buffer (500 mL) (Hanna# HI5003)HI5003 is a premium quality pH 3. 00 technical 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