Vaisala HMP3 General-Purpose Humidity and Temperature Probe
The Vaisala HUMICAP® Humidity and Temperature Probe HMP3 is designed for accurate measurement in industrial processes with moderate humidity and temperature levels. It combines high measurement accuracy with practical field maintenance for applications where calibration alone may not be sufficient to maintain performance.
The HMP3 is suitable for industrial HVAC systems, air-handling units, cleanrooms, paint booths, environmental chambers and other controlled processes. Its probe head measures temperatures from −40 to +120 °C, while relative-humidity accuracy reaches ±0.8% RH under specified conditions.
Measurement intelligence is built into the probe. The HMP3 can operate as a standalone Modbus RTU device or connect to a Vaisala Indigo transmitter for a display, analog outputs, relays and additional communication options.
Why Choose the Vaisala HMP3?
- General-Purpose Industrial Design: Suitable for ducts, chambers, process air and controlled industrial environments.
- High Measurement Accuracy: Provides humidity accuracy up to ±0.8% RH and temperature accuracy up to ±0.1 °C.
- Field-Maintainable Sensor: The HUMICAP R2 sensor option can be replaced without tools when process contamination or maintenance requirements demand it.
- Interchangeable Filters: Select a fast-response plastic grid, stainless-steel mesh or sintered stainless-steel filter according to the environment.
- Sensor Purge Options: Composite-sensor versions support sensor purge to improve chemical resistance and long-term stability.
- Standalone Modbus: Built-in RS-485 with Modbus RTU allows direct integration without a separate transmitter.
- Indigo Compatibility: Connect to Indigo200, Indigo300, Indigo510 or Indigo520 according to the required display, output and network functions.
- Traceable Calibration: Supplied with a traceable calibration certificate.
Designed for Field Maintenance
Processes containing dust, paint residue, cleaning agents or other contaminants may require more than periodic recalibration. The HMP3 allows the protective filter and selected HUMICAP sensor to be replaced at the measurement location.
Important: Humidity calibration and adjustment must be performed after replacing the field-replaceable HUMICAP R2 sensor. Replacing a filter alone does not normally require adjustment.
HMP3 Measurement Performance
| Measurement Specification | Performance |
|---|
| Relative-Humidity Range |
0–100% RH at a maximum dew-point temperature of +95 °C |
| RH Accuracy at +23 °C |
±0.8% RH from 0–90% RH |
| RH Factory-Calibration Uncertainty |
±0.5% RH from 0–40% RH; ±0.8% RH from 40–95% RH |
| RH Response Time |
15 seconds, T63 |
| Humidity Sensor Options |
HUMICAP R2, HUMICAP R2C or H₂O₂-resistant HUMICAP 180VC |
| Temperature Range |
−40 to +120 °C |
| Temperature Accuracy |
Up to ±0.1 °C |
| Temperature Sensor |
Pt100 RTD Class F0.1 according to IEC 60751 |
Operating and Environmental Specifications
| Environmental Specification | Operating Limit |
|---|
| Probe-Head Temperature |
−40 to +120 °C |
| Probe-Body Temperature |
−40 to +80 °C |
| Probe-Head Humidity |
Up to +100 °C dew-point temperature |
| Storage Temperature |
−40 to +80 °C |
| Suitable Gases |
Air, nitrogen, hydrogen, argon, helium and oxygen, subject to applicable safety requirements |
| Outdoor Use |
Suitable when installed with the correct protection and accessories |
| Probe-Body Protection |
IP66 |
Electrical and Communication Specifications
| Feature | Specification |
|---|
| Operating Voltage |
15–30 V DC |
| Current Consumption |
10 mA typical; 500 mA maximum |
| Digital Interface |
Non-isolated RS-485 |
| Communication Protocol |
Modbus RTU |
| Probe Connector |
Five-pin A-coded male M12 connector |
| Standalone Operation |
Direct Modbus RTU connection to a compatible controller or automation system |
Mechanical Specifications
| Feature | Specification |
|---|
| Probe Material |
AISI 316L stainless steel |
| Probe-Body Material |
AISI 316L stainless steel |
| Cable Jacket |
FEP |
| Probe-Head Diameter |
12 mm |
| Probe-Head Length |
Approximately 98.5 mm |
| Cable-Length Options |
0.15, 2, 5 or 10 m |
| Weight |
Approximately 302 g with a 2 m cable |
Selecting the Correct HMP3 Filter and Sensor
| Process Requirement | Recommended Choice | Reason |
|---|
| Fast humidity response |
PPS plastic grid filter |
Provides the fastest response with less physical protection |
| Typical duct or AHU use |
Stainless-steel 12 µm mesh filter |
Balances response time and particle protection |
| Heavy dust exposure |
Sintered stainless-steel filter |
Provides maximum protection from dust ingress |
| Routine field sensor replacement |
HUMICAP R2 |
Sensor can be replaced without tools, followed by calibration and adjustment |
| Chemical exposure |
Composite sensor with purge |
Periodic sensor heating helps remove absorbed contaminants |
| Vaporised H₂O₂ exposure |
HUMICAP 180VC |
H₂O₂-resistant sensor option, subject to specified operating limits |
Sensor Purge for Chemical Resistance
When the HMP3 is ordered with a compatible composite sensor, sensor purge can periodically heat the humidity sensor to remove absorbed chemicals. This helps preserve measurement performance between calibration intervals in environments containing cleaning chemicals or other contaminants.
Sensor purge can be initiated manually or configured to run at defined intervals. The field-replaceable HUMICAP R2 option and sensor-purge composite options serve different maintenance strategies and should be selected according to the process.
Use HMP3 Standalone or with an Indigo Transmitter
| Configuration | Best For | Product Link |
|---|
| HMP3 Standalone |
Direct Modbus RTU integration where no local display or analog output is required |
Current product |
| Indigo200 |
Normal single-probe transmitter with display, analog or Modbus model options and relays |
Vaisala Indigo200 |
| Indigo300 |
Intermediate single-probe transmitter for modern industrial integration |
Vaisala Indigo300 |
| Indigo510 |
Simplified flagship system using one probe in a rugged metal enclosure |
Vaisala Indigo510 |
| Indigo520 |
Flagship dual-probe system with four analog outputs, two relays and Ethernet connectivity |
Vaisala Indigo520 |
A compatible cable arrangement can extend the distance between an HMP3 and Indigo transmitter to approximately 30 m.
Common HMP3 Applications
- Industrial HVAC: Humidity and temperature monitoring in ventilation and process-air systems.
- Air-Handling Units: Duct installation for supply, return or conditioned-air measurement.
- Cleanrooms: Accurate monitoring of controlled manufacturing and laboratory environments.
- Environmental Chambers: Measurement in test and stability chambers within the specified operating range.
- Paint Booths: Field-maintainable measurement where airborne coatings may contaminate sensors and filters.
- Drying Processes: General inlet, outlet and process-air monitoring at moderate temperatures.
- Industrial Enclosures: Monitoring of equipment spaces and controlled process cabinets.
- Outdoor Measurement: Weather-protected installation using a compatible radiation shield.
HMP3, HMP5, HMP7 or HMP9?
| Probe | Main Strength | Recommended Application | Product |
|---|
| HMP3 |
Field-maintainable general-purpose 12 mm probe |
Ducts, chambers, paint booths and industrial HVAC |
Current product |
| HMP5 |
Long probe for temperatures up to +180 °C |
Ovens, kilns and high-temperature dryers |
Vaisala HMP5 |
| HMP7 |
Heated probe for continuous high humidity |
Near-condensing chambers and humid processes |
Vaisala HMP7 |
| HMP9 |
Compact 5 mm head with fast response |
Tight spaces and rapidly changing conditions |
Vaisala HMP9 |
Other Vaisala Indigo-Compatible Humidity Probes
HMP3 Installation Accessories
| Accessory | Purpose |
|---|
| Duct Installation Kit 210697 |
Adjustable installation of the HMP3 probe head in a ventilation duct |
| DTR502B Radiation Shield |
Protection from solar radiation for suitable outdoor installations |
| HMP247CG Split-Seal Cable Gland |
Installation through a wall or panel without removing the fixed probe cable |
| Magnetic Probe Holder ASM213382SP |
Temporary positioning of a 12 mm probe head on a suitable metal surface |
| Indigo USB Adapter USB2 |
Connection to Vaisala Insight software for configuration, diagnostics and calibration |
Installation and Maintenance Guidance
- Install the probe where the air or gas is representative of the process condition.
- For duct measurement, position the probe in properly mixed airflow and use the correct duct installation kit.
- Keep the probe body within its −40 to +80 °C operating limit even when the probe head is exposed to higher temperatures.
- Select the filter according to the required balance between response time and contamination protection.
- Inspect and replace contaminated filters before deposits affect response time.
- After replacing the HUMICAP R2 sensor, calibrate and adjust the humidity measurement.
- Consult Vaisala or Seacom before measuring gases or chemicals outside the specified compatible media.
Calibration and Configuration
The HMP3 is supplied with a traceable calibration certificate. Field calibration, adjustment, configuration and diagnostics can be performed using Vaisala Insight PC software, a compatible Indigo transmitter or the Indigo80 handheld indicator.
View the Vaisala Indigo80 Handheld Indicator
Vaisala HMP3 Supplier in Malaysia
Seacom Process Instruments supplies and supports the Vaisala HMP3 general-purpose humidity and temperature probe in Malaysia for industrial HVAC, cleanrooms, paint booths, environmental chambers, air-handling units and process measurement.
Our team can assist with selecting the HUMICAP sensor, protective filter, cable length, installation accessory and Indigo transmitter required for the application.
Contact Seacom for Vaisala HMP3 Selection
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