ASTM D1293

Full Name

ASTM D1293 – Standard Test Methods for pH of Water


These test methods cover the determination of pH by electrometric measurement using the glass electrode as the sensor. Two test methods are given as follows:

  1. Test Method A – Precise Laboratory Measurement
  2. Test Method B – Routine or Continuous Measurement

Test Method A covers the precise measurement of pH in water utilizing at least two of seven standard reference buffer solutions for instrument standardization.

Test Method B covers the routine measurement of pH in water and is especially useful for continuous monitoring. Two buffers are used to standardize the instrument under controlled parameters, but the conditions are somewhat less restrictive than those in Test Method A. For on-line measurement, also see Test Method D6569 which provides more detail.


hydrogen ion concentration; pH; pH buffer solution