What is the best way to measure pH in high temperature samples?

Document ID

Document ID TE3002

Version

Version 5.0

Status

Status Published

Published Date

Published Date 09/20/2018
Question
What is the best way to measure pH in high temperature samples?
Summary
pH measurements at high temperatures
Answer
Before measuring samples over 80 °C, check whether the probe is designed to stand such high temperatures. Certain gel-filled probes can be used up to 80 °C, but no higher. Refillable pH probes with saturated KCl filling solution are recommended. As KCl crystals are soluble at higher temperatures, it is a good idea to ensure the excess crystals are in solution so that the solution remains saturated. Ideally, please ensure the sample and buffer temperatures are as close as possible.