DG-4 Dewpoint Generator

Versatile control of water vapor content of an air stream

DG-4 Dewpoint Generator

Versatile control of water vapor content of an air stream

Features        Description       Specs        Downloads       Contact Us       Sable Enables

Features      Description     Specs      Downloads     Contact Us     Sable Enables


  • Regulates water vapor content of air stream based on relative humidity or dewpoint
  • Creates accurate vapor pressure or humidity profiles, even in fluctuating environments
  • Easy operation using intuitive and flexible controls
  • Solid state heat pump (Peltier effect)


The DG-4 relative humidity and dewpoint controller allows versatile control of water vapor content of an air stream. It can be operated in either a locally-controlled mode, or a computer-controlled mode that allows the generation of complex water vapor ramps and steps.

In relative humidity controller mode, the DG-4 reads the temperature of the area in which relative humidity control is required, via supplied thermistor probe. Using a saturated air stream as its input (saturator supplied with unit), the DG-4 then adjusts the water vapor content of the air stream to yield the precise set relative humidity. It does so by calculating the saturated water vapor pressure at the regulated air, using the measured temperature at that point. Then, it calculates the target water vapor pressure corresponding to the desired relative humidity entered by the user. Finally, it calculates the dew point corresponding to the target water vapor pressure and regulates its internal condensing unit at that temperature, using a solid-state heat pump.

The result is accurate, consistent relative humidity control even in the face of fluctuating environmental temperatures. This is a unique capability of the DG-4 that is invaluable for biological experimentation, product testing, protein crystallography, and other demanding applications.

Alternatively, the DG-4 can be used as a dewpoint regulator (range 1 – 45 C) or as a water vapor partial pressure regulator. Air flow rates ranging from about 25 mL/minute to 5 liters/minute can be used without affecting the system’s regulation efficiency. Condensed water is evacuated from the condenser by a miniature diaphragm pump at user-settable intervals. Alternatively, a simple plumbing change allows the user to remove condensate slowly and continuously with a user-supplied peristaltic pump.

Operation is intuitive and flexible, allowing easy operation by a wide range of users.   All adjustments and settings are permanently retained in the event of power outage.  Analog and serial data outputs are standard.

Temperature, dew point, and relative humidity data from a system controlled by the DG-4 Dewpoint Generator

Temperature (red line), dew point (green line), and relative humidity (blue line) data from a system being humidity controlled by a DG-4 Dewpoint Generator. The DG-4 Dewpoint Generator maintains an extremely stable relative humidity even under conditions of large and / or rapid temperature fluctuations.


Accuracy and Resolution: Dewpoint accuracy 0.25 C, resolution 0.01 C
Analog Output: Multi-range for relative humidity, dewpoint or water vapor pressure; 0-5 V output with 16 bit resolution
Condensate Removal: Miniature peristaltic pump, user-settable interval 1-30 minutes, actuation duration user-settable from 1 to 30 sec
Dewpoint Range: 1-45 degrees C, in 0.1 C increments
Flow Rate: 25 mL/minute to 3000 mL/minute
Operating Temperature: 5 – 35 degrees C, relative humidity non-condensing
Panel Display: Digital, 2 + 16 line alphanumeric LCD
Regulation: PID (Proportional Integral Derivative), dewpoint deviation < 0.05 C RMS typical
Relative Humidity Range: At 25 degrees C target temperature, approximately 20 – 95+ RH% attainable; settable from 0-100%RH in 0.1%RH increments
Serial Data Output: Comma delimited ASCII string of all measured parameters, standard RS-232 serial, or broadcast at user definable intervals from 0.5 – 600 seconds
Technology: Solid state heat pump (Peltier effect)
Tubing Fittings: Nickel plated barb fittings for 1/8″ (3 mm) ID flexible or semi-rigid tubing
Water Vapor Pressure Range: 0.65 kPa – 9.6 kPa, in 0.01 kPa increments
Recommended Calibration Interval: 1 Year
Power Requirements: Nominal 12 VDC at 5A; external 90-240 VAC input power supply included with unit
Dimensions (W x D x H): 8 x 9 x 10 in. (20.3 x 22.9 x 25.4 cm)
Weight: 13 lb (5.9 kg)


Brochure PDF

contact us

Please fill out the form here and our specialists will help configure the right system for your needs or provide you with a detailed quote.

To request manuals and software updates, or find warranty and service information, please contact our Support department.