Model 4PHM

Four-Port Heated Manifold

4 Port Manifold w/Heat Controller Assembly

The Four-Port Heated Manifold Accessory is a commercial-off-the-shelf manifold that has four 3/4"-16 straight thread ports. With power applied the manifold automatically controls the temperature of the manifold assembly from ambient up to 60 °C to aid in the dry down process of the frost point/dew point probes being calibrated. The manifold is equipped with a back-pressure regulator to allow the user to control the test pressure of the manifold from ambient pressure to 50 psiA if desired. The manifold supports flow rates from 1.0 to 4.0 SLPM and uses adaptable inlet and outlet fittings for connection.

Get Quote


  • 4 Port Manifold Housing made from 316 Stainless Steel
  • Heated Controller Assembly
  • Flow Rate From 1.0 to 4.0 SLPM
  • Automatically Controls Temperature up to 60 °C
  • Back Pressure Regulator
  • On/Off Fused Power Switch
  • Removable AC Power Cord
  • Dimensions 4.00" H x 6.25" W x 3.75" D
  • Assembly Weight 9.0 Lbs.
  • Manifold Inlet Tube Assembly


Controlled Manifold Temperature: 20 to 60 °C ± 1.0 °C
Voltage/Frequency: 100-240VAC, 50/60Hz
Pressure Rating (MAWP): 50 psiA
Physical Dimensions (no regulator): 4.00" H x 6.25" W x 3.75" D (102 x 159 x 96 mm)
Weight: 9.0 lbs. (4.08 kg)
Test Ports Available:3/4"-16 SAE Straight Thread Ports
Test Ports Available:G1/2 BSPP (British Standard Pipe Parallel) Thread Ports


Ambient Temperature: 18 to 26 °C
Storage Temperature: > 0 to 70 °C
Humidity: 5 to 90% Non-condensing


To provide the Model 3900 and 3920 Low Humidity Generators with the ability to calibrate four humidity sensors at the same time.

Model 4PHM with probes installed.

Typical Setup with fittings

4PHM Physical Dimensions


The 4PHM is designed to be used as an aid to calibrate 4 humidity sensors at the same time. This equates to a faster turn-around time for your calibrations. This means that each instrument will have the same accuracy and uncertainties. This manifold is specifically designed to be used with either the Model 3900 or the 3920 Low Humidity Generation Systems.

This manifold is used to aid in the dry down process of the frost point/dew point probes being calibrated for faster calibration times.

With this manifold you can connect Humidity Sensors to 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 sensors.


Model 4PHM System Documents

Model 4PHM operation manual and spec sheet for the 4PHM system.

Model 4PHM Tech Support Documents

This is a link to a complete list of support documents.

Product Accessories & Parts

These are the accessories & parts available for the Model 4PHM.

When ordering use part number 4PHM for the standard configuration and 4PHM-G1/2 for the G1/2 BSPP (British Standard Pipe Parallel) Thread Ports and when ordering any new parts for your system, be sure to specify the part numbers in bold letters or in parentheses.

Thunder Scientific does offer repair services for any of our systems, just ask for a quote today.

Need Help Getting Started?

Request a Quote.

Get a Quote Now