Some organic samples, solvents, deionized water or high temperature samples do not do well. Solvents such as acetone, toluene, methylene chloride, etc. may damage the chemical resistant epoxy at the probe tip with extended use. Then rinse the electrode well with deionized water. Use bleach solution as described above. When working with Tris buffer applications, the use of the micro pH probe is highly recommended.
All meters have a membrane keypad and are water-resistant, i.e. splashes and wet hands.
The pH probes are manufactured from 316-grade stainless steel and resist corrosion, bending and breaking. An interesting, non-published fact, however, is that the sensor and the reference junction on the slant tip style probes are recessed an approximate 1mm into the chemical resistant resin so as to prevent surface abrasion. If you turn the probe upside down so as to place the slant tip surface in a horizontal position, you will observe an approximate 1ml well created by the recessed chip and juxtaposition reference junction. You can actually obtain a reading on a single drop of fluid by dropping it into this well, covering both the pH sensor and the reference junction. The final layer has an affinity only for hydrogen ions.