Precision Hygro-Thermometer Psychrometer VS Aspirated Psychrometer

There is a clear difference between the Extech RH390 and RH490 precision Hygro-Thermometer Psychrometer versus an Aspirated Psychrometer


Aspirated Psychrometer

These units measure relative humidity using 2 thermometers, one dry and one wet (dew point). 
A reservoir of water is in the unit and a wick is attached to the wet bulb (dew point) thermometer. A small fan blows on both thermometers. The difference in temperatures determines the Relative Humidity either electronically or through a manual look-up chart using both bulb temperatures.

An aspirated Psychrometer measures Air Temperature and Dew point (wet bulb) temperature and computes Relative Humidity. These units are typically +/- 2% accurate.

 

Extech RH390 and RH490

The Extech RH390 and RH490 Measure Air Temperature and Relative humidity.The humidity sensor uses a capacitive sensor. The capacitive sensor accuracy is listed. The humidity sensor can be calibrated using the RH300-CAL calibrating salts.

These units measure Air temperature and humidity and computes the Dew point (wet bulb) temperature.

Views: 428

Reply to This

Photos

Loading…
  • Add Photos
  • View All

Members

Latest Activity

Vatche Arabian's video was featured

How to Measure LED Lights

In this video, we talk about how to measure LED lights using Extech Light Meters. For more information head to extech.com/light
Feb 2
Vatche Arabian posted a video

How to Measure LED Lights

In this video, we talk about how to measure LED lights using Extech Light Meters. For more information head to extech.com/light
Feb 2
Vatche Arabian's blog post was featured
Jan 26
Vatche Arabian posted a blog post
Jan 26

© 2016   Created by Vatche Arabian.   Powered by

Badges  |  Report an Issue  |  Terms of Service