Final answer:
The correct answer is option d. Three hours.The maximum amount of time that can elapse between obtaining a conductivity sample and taking the conductivity reading is three hours.
Step-by-step explanation:
The maximum amount of time that can elapse between obtaining a conductivity sample and taking the conductivity reading is three hours.
Conductivity is a measure of how well a material conducts electricity. It is usually measured in Siemens per meter (S/m).
In order to obtain accurate and reliable conductivity readings, it is important to take the reading as soon as possible after obtaining the sample. This is because conductivity can be affected by factors such as temperature, humidity, and impurities in the sample. Waiting too long to take the reading can result in inaccurate results.
Therefore, it is recommended to take the conductivity reading within three hours of obtaining the sample to ensure the most accurate measurement.