Extech RHT20 Humidity and Temperature Datalogger

This has always been my go to when i need dew point reading

This unit is easy to use and precise

I want to preface this review with the caveat that in order to achieve accurate relative humidity readings, this psychrometer will require the use of a 33% and 75% calibration salt kit. While they cost as much as this meter, they at least ensure accuracy, which was NOT achieved through factory calibration. As shown in the review image, the RH% reading is not calibrated we'll out of the box, but that can be expected as calibration can change in storage or shipping.I went through and returned several other psychrometers on Amazon before finally finding this one, which actually worked as described. The entire market is saturated with cheap Chinese clones where a company (sometimes reputable) slaps their name on, or changes the color of, the same generic Chinese psychrometer (often 12 degrees F or more off and unable to be calibrated). This meter, however, is unique in on the market and has the backing of the company that produced it.The calibration procedure with the Extech salt kit is easy. The meter is perfectly sized to fit within their calibration bottles and the directions are clear on how to calibrate both to 33% and 75% relative humidity.The construction of the meter exceed that of the competition as well. While It is still plastic, that plastic feels thicker and more solid than the other models on the market which feel like cheap toys. The meter reacts very quickly to changes in temperature and humidity, possibly sub-second, but does take a good 20 seconds or so to stabilize in a new environment.My goal for the meter was to establish as accurate a baseline reading for Temperature and Relative Humidity as possible for use in calibration many other sensors of varying makes and brands within my home automation system and I can gladly report that the goal has been achieved through this meter.

This item is excellent for all inspections For applications of Coatings

I bought this specifically for work, to make sure our testing labs are within spec for temp and humidity (I work in R&D). It is very easy to program, very easy to get data off of. The only criticism was that it took a little bit of messing with the data to straighten out the timestamp format to be how I wanted it, but that's not a big deal. This was a great price for a little longer like this. There's no better way to go to your boss and say "we need to replace the HVAC system" than to have a beautiful capability analysis and I-MR to back up claims of it being "weird and not good" in the room.