Most thermometers are originally calibrated to a constant-volume gas thermometer. Water temperature can be regulated with a combined thermometer and heating or cooling unit. A suitable thermometer records the pipe's temperature. In 1714, Gabriel Fahrenheit created a reliable scale for measuring temperature with a mercury-type thermometer. Temperature, as measured by an accurate, well calibrated thermometer, is empirical evidence. So, these compensate for temperature changes using an electronic thermometer and electronic logic. Technically, the temperature registered by the dry-bulb thermometer of a psychrometer. This point can be recognized by the sharp rise in temperature shown on the thermometer. This point can be recognized by the rise in temperature shown on the thermometer. The purchase of a thermometer and hygrometer are highly encouraged. A thermohydrometer is a hydrometer that has a thermometer enclosed in the float section. Examples include "thermometer" and "barometer". Psychrometers are instruments with both a wet-bulb and a dry-bulb thermometer. A mood ring is a specialized liquid crystal thermometer, wearable on the finger. The 18th century Industrial Revolution brought about such innovations as the thermometer and hydrometer.