Installation - HMM100

HMM100 Quick Guide

Document code
English (United States)
Document type
User guide
When selecting the mounting location for the probe, note the following:
  • The probe should be entirely in the measurement environment, with sufficient distance to the outer walls of the chamber or duct. Air should flow freely around the probe.
  • The probe location should represent well the environmental or process conditions, and it should be as clean as possible.
  1. Attach the module securely using the mounting holes on the corners of the component board. Use the optional mounting bracket if needed. Be sure to provide an earth connection from the plated mounting hole. See Figure 1.

    Refer to the HMM100 User Guide (M211024EN) for Vaisala order codes of accessories.

  2. Install the probe in the location. Use the optional probe mounting flange 1 or mounting clamp 2 if needed. Insert enough cable to the same space with the probe to prevent heat conduction, and to allow the probe to be moved when calibrating.
  3. Connect the wires to the screw terminals:
    • 2-wire output: see Figure 2. Provide a 24 VDC supply voltage.
    • 3-wire output: see Figure 3. Provide the required supply voltage according to the output type:
      • 10 ... 35 VDC or 24 VAC ±20 % for 0 ... 20 mA, 0 ... 1 V/5 V, and 1 ... 5 V
      • 15 ... 35 VDC or 24 VAC ±20 % for 0 ... 10 V
  4. Verify the installation: power up the module and check the output reading.
Figure 1. Component Board (3-wire Version)
Figure 2. Wiring for 2-wire Output
Figure 3. Wiring for 3-wire Output

When using the 3-wire output module, you may also connect a fourth wire to the Out - terminal. It is internally connected to the Vin - terminal. This will help reduce electrical interference, especially when using the 0 ... 1 V output.

1 Installation using mounting flange is recommended for the 400-mm-long probe option only. With the shorter, standard-length probe, this installation method increases the risk of heat conduction.
2 Use 2 mounting clamps for stability when installing the 400-mm-long probe.