It is expressed as percentage. Relative humidity does not tell how much. The warmer the air, the more water vapor it can hold. By the same token, cold air can hold significantly less water vapor than warm air. These all-in-one compact, portable, easy-to-use devices will measure and record humidity , temperature and pressure measurements.

Great for limited space applications and small enough to keep on-hand just incase.

Climate – Relation between temperature and humidity : Tables that show the effect of temperature upon the saturation mixing ratio rw are readily available. Humidity of the air at saturation is expressed more commonly, however, as vapour pressure. Thus, it is necessary to understand vapour pressure and in particular the . The RHT(also known by DHT-22) is a low cost humidity and temperature sensor with a single wire digital interface.

It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data . Wireless thermometer features built-in temperature sensor and humidity gauge to measure air temperature and humidity. Remote Monitoring System. Click More Info for full .

Sensors with an electrical transmission output for remote indication of humidity. D – Room sensors for rel. Some transmitters are mounted. Humidity and temperature transmitters for wall or duct applications with RS4or wireless communication, allowing to measure and monitor the psychrometric values for environmental or process control.

The RHT-Air is a wireless transmitter that when coupled with the . Temperature and Humidity Transmitter – RHT-Air. The HygroFlex series is a state of the art development in HVAC transmitters for relative humidity , temperature and dew point. They boast a unique calibration and adjustment process as well as many other unbeatable innovations. Visit the Kele site to learn more. These monolithic ICs combine fully calibrated humidity and temperature sensing elements, an I2C or PWM interface . The AcuRite digital humidity and temperature monitor allows you to check weather conditions at a glance.

This indoor humidity gauge and thermometer combination can be stuck to any magnetic surface or stood upright on any tabletop or countertop. The compact temperature and humidity monitor is portable, highly . Any of the three outputs can be used to trigger abode automations. The temperature , humidity , and light combination sensor provides all three sensors as different outputs.

This tutorial provides instructions for using your multi-sensor in abode automations. FREE DELIVERY possible on eligible purchases. I start reading about Smartthing.

Specifically I want to know about the attic temperature and humidity and also the same for the basement, what sensor(s) is good for this purpose? I found the Aeotec and .