Vaisala HMM100 QUICK REFERENCE GUIDE

QUICK REFERENCE GUIDE

Vaisala HUMICAP®

Humidity Module HMM100

Download

the complete User's Guide from:

www.vaisala.com/HMM100

*M211002EN*

GENERAL

The HMM100 series humidity measurement modules are open frame modules intended for integration into environmental chambers. The modules provide a single analog output channel for relative humidity (RH) or dewpoint (T Technical Data for more information.

NOTE All HMM100 series modules include

automatic temperature compensation across the operating temperature range. No external temperature compensation should be applied to the output.

NOTE The measurement probe with cable is

attached to the component board at Vaisala. Do not disconnect and reconnect the cable.

). See section

INSTALLATION

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.

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 User's Guide for Vaisala order codes of accessories.

Install the probe in the location. Use the optional probe

mounting flange or mounting clamp if needed. Insert enough cable to the same space with the probe in order to prevent heat conduction, and to allow the probe to be moved when calibrating.

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 for 0 ... 20 mA, 1 / 5 V 13 ... 35 VDC or 24 VAC for 0 ... 10 V 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 ... 1V output.

ADJUSTMENT USING TRIMMERS

HMM100 series modules have two trimmers mounted on the component board. These trimmers allow for easy adjustment of the offset and gain of the humidity measurement. The modules are shipped with the trimmers centered.

Turning the trimmer counter-clockwise will decrease the offset or gain, and turning clockwise will increase it. The adjustment range is ± 5% for both offset and gain.

Offset correction requires a < 50 %RH reference. Offset and gain correction requires additionally a > 50 %RH reference, with over 30 %RH difference between the two points.

NOTE The trimmers will only turn 135 degrees

each way, less than half a rotation. Do not force the trimmer past the stopping point.

Figure 4 Trimmers for Offset and Gain

The procedure below provides an example adjustment of offset and gain using the saturated salt calibrator HMK15. It is assumed that the module is powered and you can measure the output reading.

Note the current position of the trimmers.

Insert the probe in the LiCl salt chamber of the humidity

calibrator (11 %RH), and wait for 20 – 40 minutes for the reading to stabilize. If necessary, adjust the offset trimmer using a small

Phillips-head screwdriver to achieve the output reading that corresponds to 11 %RH.

For 4 ... 20 mA output, the reading should be 5.76 mA. For 0 ... 5 V output, the reading should be 0.55 V.

Insert the probe in the NaCl salt chamber (75 %RH) and

wait for the reading to stabilize. If necessary, adjust the gain trimmer to achieve the

output reading that corresponds to 75 %RH. For 4 ... 20 mA output, the reading should be 16 mA.

For 0 ... 5 V output, the reading should be 3.75 V. Optional: repeat steps 2 – 4 to check the adjustment result.

If you want to undo the adjustment, return the trimmers to their original position.

Visit our Internet pages at www.vaisala.com

TECHNICAL DATA

Property Description / Value

Measured parameters Relative humidity Dewpoint

Accuracy

-20 ... +40 °C

-40 ... -20 °C, +40 ... +180 °C

Sensor Vaisala HUMICAP® 180R Outputs 2-wire 3-wire Supply voltage 2-wire 3-wire (0 ... 20 mA, 1 / 5 V)

3-wire (0 ... 10 V) Input current < 4 mA Connections Screw terminals,

Probe types and cable lengths Plastic, 0.6 m cable

Sensor protection options Plastic grid filter

Operating temperature range Component board Probe (both types) Plastic grid and membrane filter PTFE and stainless steel filter

Ref. M211002EN-A

0 ... 100 %RH

-20 ... +100 °C (-4 ... +212 °F) Td

± 2 %R

H (0 ... 90 %RH)

± 3 %RH (0 ... 100 %RH) ± 2.5 %RH (0 ... 90 %RH) ± 3.5 %RH (0 ... 100 %RH)

4 ... 20 mA (loop powered) 0 ... 20 mA, 1 / 5 / 10 V

24 VDC 10 ... 35 VDC or 24 VAC

13 ... 35 VDC or 24 VAC

0.5 ... 1.5 mm2

4-pin M8 connector for service use

Plastic, 1.55 m cable Plastic, 2.9 m cable Stainless steel, 1.55 m cable Stainless steel, 2.9 m cable

Membrane filter Porous PTFE filter Stainless steel sintered filter

-5 ...+55 °C (+23 ... +131 °F)

-70 ...+180 °C (-94...+356°F)

-20 ... +80 °C (-4 ... +176 °F)

-70 ...+180 °C (-94...+356°F)

Figure 5 Dimensions in mm