3900 Humidity Generator

The Model 3900 Low Humidity Generator is an extremely accurate means of producing known humidity values for calibrating and verifying humidity instrumentation. Based on the combined, NIST proven, fundamental “two-pressure” and “two-temperature” principles, this system will automatically supply a continuous humidified gas stream, within the frost/dew point range of –95.0 °C to 10.0 °C, for days or even weeks unattended. Simply apply power to the system, and the 3900 will power-up ready to purge and/or generate. Humidity setpoint values are input by the operator from the front panel keypad and are limited only by the operational range of the 3900 humidity generator.

  • Traceable to SI
  • Based on NIST Proven Two-Pressure Principle
  • Push Button (Keypad) Control
  • Automated Control of User Setpoints
  • 3900 ControLog® Automation Software
  • HumiCalc® with Uncertainty Software
  • Automatically Applies Enhancement Factors
  • Computerized Internal Transducer Calibration
  • RS-232C Serial Interface
  • Only Nine Square Feet of Floor Space
  • Timed/Formatted Output to Printer
  • Battery Backed-up Real Time Clock
  • Backlit Liquid Crystal Display
  • Frost / Dew Point Range: –95 to +10 °C
  • Frost / Dew Point Uncertainty: (–95 to –90 °C) 0.9 °C, (–90 to –80 °C) 0.5 °C, (–80 to –70 °C) 0.2 °C, (–70 to 10 °C) 0.1 °C
  • Parts Per Million Range: 0.05 to 12000 PPMv
  • Relative Humidity Range 0.0002 to ~50%
  • Saturation Pressure Range: Ambient to 300 psiA
  • Saturation Pressure Uncertainty (10-50 psiA): 0.05 psiA
  • Saturation Pressure Uncertainty (50-300 psiA): 0.30 psiA
  • Saturation Temperature Range: –80 to +15 °C
  • Saturation Temperature Uncertainty: 0.08 °C
  • Saturation Temperature Heating/Cooling Rate: 2 Minutes Per °C Average
  • Test Pressure Range: Ambient to 50 psiA
  • Test Pressure Uncertainty (10 – 50 psiA): 0.05 psiA
  • Test Pressure Range (Option): Ambient to 150 psiA
  • Test Pressure Uncertainty (10 – 150 psiA)(Option): 0.05 psiA
  • Test Temperature Range: 0 to 50 °C
  • Test Temperature Uncertainty: 0.08 °C
  • Display Resolution: 0.01
  • Gas Flow Rate Range: 0.1 to 5 L/min
  • Gas Flow Rate Range (Option): 0.5 to 10 L/min
  • Gas Flow Rate Resolution: 0.02 L/min
  • Gas Flow Rate Uncertainty: 0.2 L/min
  • Gas Type: Air or Nitrogen
  • Gas Pressure Rating (MAWP): 350 psiG
  • Refrigeration: 1/3 HP R-134A & 1/3 HP R-23 in Cascade
  • Heating: Stainless Steel Immersion Heaters
  • Test Port: 1/4 Inch Swagelok® Tube Fitting (6.35mm)
  • Physical Dimensions: 37.5″ H x 23″ W x 30″ D (953mm x 584mm x 762mm)

Virtually any humidity may be generated, for any length of time, within the operational limits of the generator. The output of the device under test may then be compared with the generator’s printed data for analysis.

Chilled Mirror Hygrometers: Connect the generator output to your chilled mirror hygrometer and you can: verify mirror temperature measurement accuracy (calibration) when the hygrometer is in thermal equilibrium with its environment; perform operational checks of the heatpump and optical components, before and after mirror cleaning and balancing; determine whether the hygrometer is controlling the mirror deposit in the liquid phase or ice phase when operating at dew and frost points below 0 °C; determine if the hygrometer is correctly calculating other humidity parameters; determine hygrometer repeatability, stability, and drift characteristics.

Humidity Sensors and Electrolytic Hygrometers: Connect the generator output to your Electrolytic Hygrometer, sampling system, special fixtures, or sensors and you can: determine humidity calibration accuracy and/or characterize humidity sensitivity by subjecting the humidity sensor to a variety of humidity levels; perform operational checks such as the sensing systems capability to correctly calculate and display other humidity parameters; determine repeatability, stability, hysteresis, and drift characteristics of various humidity sensing systems.

Environmental Testing: The 3900 can serve as a test bed for evaluation and R&D of humidity sensors, humidity sensing systems, and humidity sensitive products, e.g., polymers, composites, film, magnetic medium, pharmaceuticals, soil hydrology, consumables, electronics, optics, etc.

You can upgrade with several different options for the Model 3900.

High Air Flow (HAF-39) Higher air flow rate (0.5 to 10 L/min).

High Pressure Transducer (HP) (150 psiA).

Back Pressure Regulator (REG) Please specify the range needed for your application.

Different styles of sample cell manifolds are available, like the Vaisala model DMP248SC, specify (SCM4) for the 4 cell option and (SCM6) for the 6 cell option. Another option available is the Panametrics 2830, ask for the (2830) and you will receive the 4 cell manifold option.

3900 ControLog Automation Software (3CL) Allows the 3900 to communicate with various test instruments.