Extech RH350 Psychrometer with 2 Type K Remote Temperature Probes

Purchased 3 of these units to check due point for construction painting work. My guys really like the ease of use and the accuracy of the Extech RH350. We have more expensive brands but found we needed units more user friendly and faster to use. The RH 350 has worked well for our crews. Con, Need good case to protect unit, case is not provided with unit.

First off, this meter seems like an excellent value if your goal is to sample air quality or temperature data. It has both a serial output and a 1/4” tripod mount. The only issue is Flir (that now owns Extech) discontinued the RS-232 cable. Second, I could not get the official 589250 cable working with a USB to serial converter. In fact the first meter I received may have been damaged by this arrangement since Extech neither mentions anything about how the cable is configured nor has any warning about what the requirements are for the serial port you are connecting it to.The good news is I figured out how it works. The meter has a 3.5mm TS mono jack. Where the tip is positive and sleeve is ground. The meter sends data at 3.3v on the tip. To receive data from this meter obtain a 3.5mm mono plug cable of appropriate length to your needs and a USB to TTL serial adapter capable of working at (CMOS) 3.3v levels. Connect the tip wire to RX and the sleeve wire to ground. The data is sent at 9600 8N1 in plain text and can be logged by any serial terminal software or by using Extech data logging software available on Flir’s website.

Decided to buy this because it was half the price of the fluke one and I'm a fluke guy. Good thing I didn't because I calibrated this with a fluke pyschrometer one of my customers had and this one was more accurate. It does not feel very heavy duty or durable so take care of it.

Nice size for fitting in tool kit and great accuracy!

Very cheap feel to it. Not at all accurate. Very unhappy with purchase

T2 port broke internally already, very light, cheap feel in the hand

We are using this at our Self Storage facility to verify temperature and humidity settings in our Climate Control Storage. The readings are quick and accurate and allow us to control costs while meeting the needs of our tenants.

Does the job quite well especially for the money. Only thing I'm concerned about are the temperature probes. I'm concerned about wire fatigue over time. However, there are two of them. I only use one at a time.