Hygrometers
19th and Early 20th Century Hygrometers
This is what hygrometers looked like in the 19th and early part of the 20th century. For the most part they worked OK, correctly charting the humidity, but they were very delicate, easily upset and needed frequent calibration. Some would record temperature also but they were all mechanical and needed frequent maintenance. They were expensive to purchase and required paper charts and pens which had to be replaced at regular intervals. These ongoing cost made them expensive to own. They also only recorded the temperature and humidity where they were located. If you wanted to measure and record the environmental conditions in two or three areas you needed two or three hygrometers; one for each area.
Sadly many businesses are still using these antiques when they could actually move into the 21st century and save labor and money by doing so.
A 21st Century Hygrometer
It is electronic, has no moving parts, can measure and record the humidity and the temperature in four different areas; some quite remote from the actual hygrometer. It uses four wireless sensors, does not need any maintenance at all and only needs to be calibrated every year or so. And, unbelievably this sleek looking instrument with four times the capacity and many additional features cost about the same or less than the old-time mechanical hygrometers. Even better, it does not need any paper charts or pens, can be viewed remotely on a computer and its charts can be stored electronically and even emailed to others.
The problems inherent in older mechanical hygrometers are eliminated since there are no moving parts. The sensors are digital, so they stay in calibration for long periods of time and are easily re-calibrated with a three-point calibration table built into each sensor. Often the old type of mechanical hygrometer would be ‘flicked’ by a someone causing the instrument to, no only stop working, but also to need re-calibration. Visitors can not upset the recording mechanism of this paperless Hygrometer because it is all digital. And the sensors themselves are enclosed in a small plastic box along with a wireless transmitter, to protect them from inquisitive visitors.
Each Sensor is Digital and Wireless
Each sensor samples temperature and humidity every few seconds, storing the logged data in its internal memory. And, since the sensors are wireless, installation is a snap: Just position the wireless sensors in the areas you want to monitor or alarm and mount the display unit on the wall in a central location. Where it is mounted does not really matter, as it is password protected so unauthorized people can not change the settings. The sensors can even be put in enclosed cases. The range is: over 60 feet, clear line-of-sight. There are no worries about unauthorized personnel messing up the settings as everything is password protected.
Monitor, Log, Chart and Alarm
Another big difference between the electronic Hygrometer and the old mechanical hygrometers is that it not only records the humidity on a continuous basis, but the resulting chart can be set to Email, Text, or alert by phone multiple people if the humidity or temperature ever gets too low or high.
It is quickly replacing the old mechanical hygrometer in museums, art galleries, computer rooms, clean rooms, testing labs, laboratories, etc.. to provide accurate temperature/humidity monitoring.
The temperature and humidity data logged by the monitor can be downloaded to a computer either on demand or continuously so charts or numeric data can be printed out, saved to files or even emailed to lending institutions.
The digital hygrometer’s sensors are accurate to ±3% or even 1.5%. They are guaranteed to stay within calibration for two years. The old sling psychrometer used to re-calibrate the old drum type hygrometers can be thrown away.
Used where Maintaining Temperature and Humidity is Critical
![]() Testing Laboratories |
![]() Art Galleries |
![]() Storage Areas |
View the Temperature and Humidity History any Time
Each TV2 Hygrometer comes with either a wired Ethernet or WiFi connection so it can be accessed by a computer to automatically download the logged data every few minutes. The copied data is added to files stored in your
network so it can be made instantly available to anyone with a computer or even a phone. Real time or historical data charts can be viewed on the computer screen and printed for any period of time.
Having a data log of temperature and humidity available at any time saves valuable personnel time and effort. There is no need to transcribe hand written information when it is requested by customers or quality control.
Note: The data shown here was logged every minute which is not the way most people have the Digital Hygrometer setup usually. Most often data is logged every 10 minutes or even once an hour depending on the application. The logging rate can even be set to log once or twice a day.