Munro Instruments Ltd products

This compact, rugged hygrometer provides accurate measurements of relative humidity, air temperature, vapour pressure and barometric pressure. It is supplied with a radiation shield to protect it from dust and liquid, whilst ensuring adequate airflow to the sensor. For indoor monitoring applications, use of the radiation shield is not critical, providing the sensor is not exposed to solar radiation or other direct sources of heat. The instrument comprises both a capacitance humidity sensor and a bandgap temperature sensor. Measurements are taken simultaneously and are used to calculate the vapour pressure. Barometric pressure is measured using a secondary sensor chip. The hygrometer responds quickly to changes in the temperature and humidity and has very minimal long-term drift. It is recommended that the sensors are calibrated at least once every two years to ensure continued accuracy.

This highly precise hygrometer is an excellent solution for those who need to monitor humidity and temperature. Humidity is measured by a capacitative sensor made of a hygroscopic polymer. The sensor works by detecting changes in the dielectric constant, which is directly proportional to the relative humidity of the surrounding environment. The advantages of this type of sensor include insensitivity to temperature changes, quick response time and durability. The temperature sensor is a platinum resistance thermometer (100Ω at 0°C). The Pt100 resistance variation is transformed into a current or voltage signal linear to temperature.