Extech RH30 Hygro-Thermometer with Humidity Alert

Extech RH30 Hygro-Thermometer with Humidity Alert


The Extech RH30 monitors temperature, humidity, and dew point and sends alerts to notify of unfit conditions.


  • Beeper sounds and bright LED flashes when humidity level exceeds user preset
  • Large, easy-to-read triple LCD displays
  • Desktop stand can be removed for wall mount use
Your Price
Usually ships in 3-5 days

Shipping Information
Return Policy
Why Buy From Fondriest?


The RH30 is a large, easy-to-read triple LCD that simultaneously displays relative humidity, temperature, and dew point measurements. A beeper sound and bright LED flash when humidity levels exceed user preset amounts. Temperature variables can be switched from °C to °F and vice versa. The desktop stand can be removed to mount the unit to a wall. Applications include laboratories, R&D, clean rooms, and bio-pharmaceutical manufacturing facilities, museums, and storage and document archive facilities.

Notable Specifications:
  • Relative Humidity Measurement Range: : 1.0 to 99.0% RH
  • Air and Dew Point Temperature Measurement Range: ‐10 to 50°C (14 to 122°F)
  • Air and Dew Point Temperature Resolution: 0.1 °C (°F) and %
  • Humidity Accuracy: ±4% from 35% to 75% otherwise ±5%
  • Temperature Accuracy: ±1.0°C (1.8°F) 
  • Power Supply: 2 x 1.5V AA batteries
  • Dimensions: 95 x 25 x 95 mm (3.7 x 1.0 x 3.7")
  • Weight: 90 g (3.2 oz.) instrument only, batteries not included in weight spec.
What's Included:
  • (1) Hygro-thermometer
  • (2) AA batteries
Image Part # Product Description Price Stock Order
Extech RH30 Hygro-Thermometer with Humidity Alert RH30 Hygro-thermometer with humidity alert
Usually ships in 3-5 days

In The News

US Steel Dumping Chromium: Citizens Fighting for Lake Michigan, and Drinkable Water

If you remember the movie “Erin Brockovich,†you are already familiar with hexavalent chromium, a toxic substance that was contaminating the drinking water of people in California in the movie ( and in real life ). Although on the silver screen there was a very satisfying Hollywood resolution to the problem, there has not yet been such a happy ending in real life. The dumping of the hexavalent chromium by PG&E that the film documented took place in the 1950s and 1960s, although the company didn't tell anyone about the problem until the late 1980s. Based on current litigation around the Illinois and Indiana shores of Lake Michigan, startlingly little has changed.

Read More

Monitoring the Mississippi: Wild Celery, Redhorse and More

The Upper Mississippi stretches from headwaters at Lake Itasca, Minnesota, all the way to Cairo, Illinois, about 1,250 miles. It includes picturesque wilderness areas complete with waterfalls, limestone bluffs and expansive valleys. It has attracted many campers, hikers, fishing enthusiasts and people seeking to launch their favorite boats or canoes. It has also been a haven for environmental researchers. Since 2016, Jeff Houser is the Science Director for the Long Term Resource Monitoring element (LTRM) of the Upper Mississippi River Restoration Program (UMRR).  Previously, he led the LTRM water quality component from 2003 until 2016.

Read More

BOB and MARI Will Monitor Water Chemistry in the San Francisco Bay

Scientists have had nagging questions about how ocean acidification might be affecting the waters of the San Francisco Bay. But if you can't trust BOB and MARI with your research questions, who can you trust? That's BOB, the Bay Ocean Buoy and MARI, BOB's companion mooring for Marine Acidification Research Inquiry, of course. BOB and MARI are a bright yellow, five-foot tall buoy and its companion mooring, respectively. They are anchored near the Estuary and Ocean Science (EOS) Center of San Francisco State University (SFSU). SFSU researchers are collaborating with scientists from the University of California, Davis and other funders and partner organizations on the first long-term project to monitor carbon dioxide and ocean acidity in the San Francisco Bay.

Read More