A thermometer hygrometer is a device that is used to measure both the current air temperature and the relative humidity at a particular location. The temperature is typically measured in degrees Fahrenheit or Celsius, and the unit might show the indoor temperature, outdoor temperature, or both. Relative humidity refers to how saturated with water vapor the air is, and it is usually shown as a percentage. A temperature hygrometer will commonly be either a dial instrument or a digital one.
How do i use outdoor hygrometer:
A hygrometer is a device that senses relative humidity. This technology, sometimes coupled with thermometers, allows monitoring of humidity conditions for numerous industrial, commercial, and residential applications. An outdoor hygrometer differs from the indoor type in several ways: it is typically weatherproof, and provides readings over a greater range with less precision than indoor types. Determine whether you need to spot check or monitor humidity, the intended placement of the unit, and if you need to use a datalogger for computer tracking.
To ensure the most accurate readings, you can use a psychrometer, or wet-and-dry bulb thermometer, to calibrate a hygrometer. Devices are sometimes protected under solar radiation shields or ventilated housing. They should not be placed in direct sunlight or precipitation.
Humidity is the degree of moisture present in the atmosphere. To best place an outdoor hygrometer, you must consider qualities of ventilation, heat absorption of the ground, and air and water table flow, all of which can skew readings. In other words, a hygrometer should be placed about 5 ft (about 1.5 m) above ground in a level, open space. It should be placed ideally above trimmed grass, which permits air between the sensor and the ground to mix. Hard ground radiates temperatures more intensely; slopes divert water table and air flows, thus distorting readings.