HMP3 General Purpose Humidity and

Temperature Probe

Features

• Available with field-replaceable

HUMICAPâ R2 sensor

• RH accuracy up to 0.8 %RH

• Temperature accuracy up to 0.1 °C

(0.18 °F)

• Temperature measurement range

−40 … +120 °C (−40 … +248 °F)

• Sensor purge improves long-term

stability and chemical resistance

• Modbusâ RTU over RS-485

• Compatible with Vaisala Indigo

products and Insight PC software

Vaisala HUMICAPâ Humidity and Temperature Probe HMP3 is a general-purpose

probe designed for various industrial processes. The probe structure allows for

replacing the sensor without tools, making the probe suitable for applications such as

paint booths and other industrial applications where periodic recalibration alone is not

sufficient for maintaining the probe performance. Other applications include, for

example, industrial HVAC systems, cleanrooms, and environmental chambers.

Designed for field

maintenance

Probe design allows for several operating

environments and flexible field

maintenance. Filter and HUMICAPâ R2

sensor element are field replaceable for

applications that require frequent

replacements. Calibration and

adjustment of humidity measurement is

also needed if the HUMICAPâ R2 sensor

is replaced. The following filter types are

recommended for HMP3:

• Stainless steel mesh filter (12 µm mesh

size) for typical applications such as air

handling units

• Sintered stainless steel filter for

applications where maximal protection

from dust ingress is essential

• PPS plastic grid filter for best humidity

response time

Sensor purge available with

composite sensors

If purchased with a composite sensor

instead of the field-replaceable

HUMICAPâ R2 sensor, HMP3 can use the

sensor purge feature. In environments

with high concentrations of chemicals

and cleaning agents, sensor purge helps

to maintain measurement accuracy

between calibration intervals.

Sensor purge involves heating the sensor

to remove harmful chemicals. The

function can be initiated manually or

programmed to occur at set intervals.

Flexible connectivity

The probe can be used as a standalone

digital Modbus RTU transmitter over an

RS-485 serial bus, and it can also be

connected to Indigo transmitters and the

Indigo80 handheld indicator. For easy-

to-use access to field calibration, device

analytics, and configuration functionality,

the probe can be connected to Vaisala

Insight software for Windowsâ. For more

information, see www.vaisala.com/

insight.

Vaisala Indigo product family

Indigo transmitters extend the

capabilities of Indigo-compatible

measurement probes. The transmitters

can display measurements on the spot as

well as transmit them to automation

systems through analog signals, digital

outputs, and relays. Cable length

between probe and transmitter can be

extended to up to 30 meters.

The Indigo80 handheld indicator is ideal

for spot-checking and process

monitoring, as well as for configuring,

troubleshooting, calibrating, and

adjusting the probe. For more

information, see www.vaisala.com/

indigo.