Final answer:
Thermistors should be placed at the point where an accurate temperature measurement is desired, such as under the tongue in digital medical thermometers. Their temperature-dependent resistance is key in automated temperature measurement, making their placement vital for reliable readings.
Step-by-step explanation:
Thermistors are commonly used in various types of thermometers due to their temperature-dependent resistance. To measure temperature accurately with a thermistor-based device, the thermistor should be placed at the point where the temperature measurement is desired. For example, in digital medical thermometers, the thermistor is positioned so that it can be at the same temperature as the patient, such as under the tongue in oral thermometers, to ensure that the resistance reading it provides reflects the patient's body temperature accurately.
Furthermore, the property that the resistance of a thermistor changes with temperature is utilized in many automated temperature measuring instruments. This quality makes thermistors very useful for providing quick and accurate temperature readings in various settings, such as medical diagnoses, environmental monitoring, industrial processes, and more. The precise placement of the thermistor is critical for obtaining reliable measurements, making it a vital component in the design of temperature measurement devices.
In the case of the digital medical thermometer, the resistance of the thermistor is compared to its known resistance at a reference temperature (typically 37.0°C) to determine the patient's temperature. This process is automated and provides a readout indicating the temperature of whoever is being measured.