Delmhorst Instrument

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  • Ranges:
    • Relative humidity: 0 to 100%
    • Temperature: -40 to 255°F (-40 to 124°C)
    • Dew point: -40 to 176°F (-40 to 80°C)
    • GPP: 0.1 to 3820 GPP (0.01 to 545 GPK)
    • Vapor pressure: 0 to 7 PSI (0 to 47 KPa)
  • Bright, clear digital display
  • Built-in back-light makes reading in dark places a cinch
  • Auto shut-off timer saves battery life
  • Reading HOLD Feature
  • Size: 8-1/2 x 3-3/8 x 1-3/4, weighs just 11 ounces
  • Rugged construction ensures years of reliable use
  • 9V battery
  • 1-year warranty

What's in the Box

  • RH/T-S1 sensor
  • 324CAS-0098 case

The Delmhorst HT-4000 is a stand-alone thermo-hygrometer that has the same fast acclimating RH/T sensor found in Delmhorst's popular Navigator Pro 3-in-1 moisture meter. For contractors who prefer having separate meters to one combination meter, the HT-4000 is the perfect solution.

The HT-4000 thermo-hygrometer measures relative humidity from 0 to 100%; temperature from -40 to 255°F (-40 to 124°C); dew point from -40 to 176°F (-40 to 80°C); grains per pound from 0.1 to 3820 GPP (0.01 to 545 GPK); and vapor pressure from 0 to 7 PSI (0 to 47 KPa). Results are shown on the bright, clear digital display. A built-in back-light makes reading in dark places a cinch.

The HT-4000 features rugged construction to ensure years of reliable USE. It includes automatic power down and a HOLD feature.


Delmhorst RH/T-S1 Relative Humidity/Temperature Sensor
Detachable version of the same relative humidity/temperature sensor that is included with Navigator Pro and HT-4000


Delmhorst RH/TK Relative Humidity Test Kit
Testing kits for relative humidity at 33% and 75% levels


Delmhorst RH/T-C1 Cable
3-foot extension cable that connects the RH/T-S1 detachable sensor to the Navigator Pro or HT-4000


Please consider these optional accessories.

Delmhorst Certificate of Conformance
Delmhorst Certificate of Conformance with serial number
Call for pricing


This product can be used in the following applications: