DEWRanger-DUO Portable Hygrometer


The DEWRanger DUO hygrometer is a fully portable instrument for making spot checks of the absolute moisture content of industrial gases. It can also be used for longer term measurements. It is powered either from its internal re-chargeable battery or from a mains supply of 90-250Vac. The instrument consists of a STORK Instruments DEWCom dewpoint transmitter which is fitted in a special Desiccant Head. These are installed in a robust Peli industrial case.



  • Dewpoint Measurement Ranges: -100°C to +20°C dewpoint (-148° F to +68° F dewpoint), g/m3, 0-9999 ppmv; 0-1000 lb/mmscf for natural gas
  • Electronic accuracy: PPMV range ±1% of reading, LB/MMSCF range ±1% of reading
  • Dewpoint accuracy: ±2°C
  • Temperature coefficients: temperature compensated
    from –20°C to +40°C
  • Operating temperature: 0 to +40°C
  • Operating environment: 0°C  to +40°C, 0 to 90%RH
  • Output: 4 - 20 mA output
  • Environmental protection: IP67
  • Flow rate: Recommended  1-5  liters  per  minute
  • Interchangeability:Fully interchangeable sensors                                                                             


Routine maintenance of the STORK DEWRanger hygrometer is confined to regular re-calibrations. This work can only be done by exposure of the moisture sensor to sample gases of known moisture content.
The frequency of re-calibrations required in order to maintain the performance of the  hygrometer is primarily dependent on the composition of the gas to which the sensor is exposed: i.e. content of liquid and particulate contaminants, corrosive elements, etc. In most applications, annual re-calibration ensures that the stated accuracy of the  hygrometer is maintained.
The Dewcom sensor is fully interchangeable. Maintaining the measurement accuracy of the Dewranger DUO hygrometer in is simply a case of exchanging the sensor for a freshly calibrated one, which will be supplied with a traceable certificate of calibration.



Dewpoint Detector: Stork Instruments advanced bi-ceramic Dewpoint Transmitter




Flow rate:

Operating Temperature:

Power supply:

Ingress protection:


-100°C to +20°C, -148°F to +68°F, 0 to 9999 ppmv,
0 to 1000 lb/mmscf, g/m3 set by interface unit

+/- 2°Cdp

max 1-5 l/min

0°C to +40°C, 0 to 90%RH

50mm x 38mm graphic

analog 4-20 mA


Peli 270 x 246 x 174mm


4,4 kg








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