Glossary for Temperature and humidity sensor

Temperature and humidity sensor

The capacitive relative humidity sensor and the band gap temperature sensor, it is a sensor that can measure the temperature and humidity at one.

Relative humidity

That the amount of saturated water vapor that can be included in the air (the maximum amount water vapor: 100), and represents the amount of the actual steam percentage in certain temperature.

Saturated water vapor

The amount of the maximum water vapor that can be included in the space is called a "Saturated water vapor amount", it is known that the pressure at that time the.
The saturated water vapor content that can be included in air (saturated water vapor pressure) is increased as the temperature is warm, it reduces to become cold.

Condensation

The term "condensation" is a phenomenon where water vapor in the air (gas) is water (liquid) when it reaches a certain temperature or lower.
That the change from a gas to a liquid is called the dew point, and refers to the temperature at that time and the dew point temperature.
Dew point of the "temperature 20 °C / humidity of 60 %" is about 12 °C, but the dew point of the "temperature 20 °C / humidity of 40 %" is about 6 °C, it'll be different depending on temperature and humidity.

Humidity response speed

Step change (90 % RH from 10% RH), the output signal represents the time it takes to follow up to 63 percent.
(25 °C, and put on the air flow rate 1m/s)

4 to 20 mA output

Form of an analog signal of industrial.
The format is superior to the noise immunity than the voltage output.
Since the minimum value of 4 mA, it can detect the disconnection (0 mA).
By inserting a shunt resistance (250 Ω (1 / 4 W or more)), "current - voltage conversion" also is a possible conversion to 1 V to 5 V signal carried out.

1 to 5 V output

As well as the 4 mA to 20 mA, the form of analog signal of industrial.
Since the minimum value is 1 V, it will be able to detect disconnection of the (0 V).