5 TCO 8 A medical technologist reports that a pH meter in th

5. (TCO 8) A medical technologist reports that a pH meter in the clinical lab has an output that wanders about an apparently correct pH value. What part of the device should probably be replaced? How do you know? (Points : 17)

Solution

Probe of the device needs to be replaced.

Probe is a rod-like structure usually made of glass, with a bulb containing the sensor at the bottom. Frequent calibration with solutions of known pH, perhaps before each use, ensures the best accuracy. To measure the pH of a solution, the probe is dipped into it.

Probes need to be kept clean of contamination as far as possible, and not touched by hand.