What is a common method to test the accuracy of a thermostat?

A common method to test the accuracy of a thermostat is by comparing it with a calibrated thermometer. This method provides a direct way to assess whether the thermostat is correctly measuring the temperature of the environment.

Using a calibrated thermometer allows for a benchmark to determine the thermostat's accuracy. The calibration ensures that the thermometer provides precise readings, which can then be used to see if the thermostat’s display matches the true temperature. If there is a discrepancy, adjustments or repairs may be necessary to ensure accurate heating and cooling.

The other methods, while useful in different contexts, do not provide a direct evaluation of the thermostat's accuracy. For instance, using a digital multimeter primarily measures electrical voltage and current, which doesn't directly reflect the temperature accuracy. Checking against the outdoor temperature can be misleading due to environmental factors affecting indoor readings. Lastly, a visual inspection of the wiring might identify issues with the physical connections, but it won't determine if the thermostat is accurately reading the temperature.