The Vaisala HMP3 is a high-accuracy, field-maintainable probe for industrial HVAC, air-handling units, cleanrooms, paint booths and environmental chambers.
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.
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.
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
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.
| 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.
| 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 |
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 HMP1, HMP3, HMP4, HMP5, HMP7, HMP8 and HMP9 can be connected to the Vaisala Indigo80 Handheld Indicator using a compatible connection cable.
Portable measurement and field servicing: use Indigo80 to display live humidity and temperature readings, record measurement data, check probe performance, configure settings, and perform field calibration and adjustment. The same Indigo80 can support different compatible probes, making it practical for servicing multiple measurement points.
Vaisala Indigo-compatible HMP probes share the same measurement platform, but their mechanical design and installation method suit different conditions. Use the table below to identify the best starting point for your application.
| Probe | Main strength | Recommended application | Product |
|---|---|---|---|
| HMP1 | Compact wall-mounted probe for indoor environments | Cleanrooms, laboratories, data centres, warehouses and demanding HVAC | Vaisala HMP1 |
| HMP3 | Field-maintainable general-purpose 12 mm probe | Ducts, chambers, paint booths, air-handling units and industrial HVAC | Vaisala HMP3 |
| HMP4 | High-pressure measurement up to 100 bar | Compressed air, breathing air, industrial gases and vacuum systems | Vaisala HMP4 |
| HMP5 | Long probe for high temperatures up to +180 °C | Ovens, kilns, baking processes and high-temperature dryers | Vaisala HMP5 |
| HMP7 | Heated probe for continuous high humidity | Near-condensing chambers, humidifiers, drying processes and other persistently humid conditions | Vaisala HMP7 |
| HMP8 | Adjustable-depth probe for pressurised pipelines | Compressed-air lines, refrigerant dryers and industrial pipelines requiring easy probe removal | Vaisala HMP8 |
| HMP9 | Compact 5 mm probe head with fast response | Tight spaces, rapidly changing air, compact equipment, ducts and data centres | Vaisala HMP9 |
Quick selection: choose HMP1 for wall mounting, HMP3 for general industrial measurement, HMP4 for pressure up to 100 bar, HMP5 for high temperature, HMP7 for continuous high humidity, HMP8 for removable installation in pressurised pipelines, or HMP9 where space and response time are the main concerns.
All seven probes can operate as standalone Modbus RTU instruments or connect to a compatible Vaisala Indigo transmitter. Final selection should also consider temperature, pressure, humidity level, chemical exposure, installation depth, cable length and required outputs.
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.
The Vaisala Indigo200 Series is the standard transmitter platform for one interchangeable Indigo-compatible smart probe, providing local display and practical automation-system connectivity.
The Vaisala Indigo500 Series provides flagship industrial measurement integration: choose Indigo510 for a simplified single-probe system or Indigo520 for full dual-probe capability.
The Vaisala Origo10 Series comprises modular HVAC transmitters with interchangeable probes for humidity, temperature, CO2 and dew-point measurement.
Available with analog, Modbus RTU and BACnet MS/TP outputs, wall or duct mounting, an optional display and an IP65-rated enclosure.
The Vaisala HMP8 provides high-accuracy humidity and temperature measurement in compressed air, refrigerant dryers and pressurised industrial processes up to 40 bar.
The Vaisala MGP261 measures methane, carbon dioxide and humidity directly in raw biogas. Its in-situ design avoids a separate sampling system and helps operators monitor gas quality while protecting downstream equipment.
The Vaisala HMT360 Series was an intrinsically safe transmitter platform for humidity, temperature and moisture measurement in hazardous areas. It is discontinued and replaced by the Vaisala HMT370EX with an application-specific probe.
The Vaisala HMD60 Series provides high-accuracy humidity and temperature measurement for demanding HVAC ducts and light-industrial applications.
The Vaisala XMW85 Series provides reliable indoor CO2, humidity and temperature measurement for demand-controlled ventilation, smart buildings and indoor air-quality monitoring.
All models support Modbus RTU over RS-485, with two-in-one and three-in-one measurement configurations and optional metric or non-metric displays.
The Vaisala HMP7 is designed for continuously humid, rapidly changing and near-condensing environments. Probe heating helps prevent condensation while maintaining reliable process measurement.
The Vaisala Indigo300 is a rugged industrial transmitter for one Vaisala Indigo-compatible smart probe, providing local measurement display and up to three configurable analog outputs.
Its corrosion-resistant IP66 metal enclosure, flexible probe mounting and interchangeable probe design make Indigo300 suitable for humidity, temperature, dew point, CO2, moisture in oil and other demanding industrial measurements.
The Vaisala XMP10 Series comprises compact humidity and temperature probes offering accuracy levels up to ±1% RH and ±0.1 °C for demanding HVAC, data-centre and critical-environment applications.
The probes feature analog or Modbus RTU outputs, a standard M8 connector, an IP65-rated body and compatibility with Vaisala Origo10 modular HVAC transmitters.
The Vaisala GMW90 Series provides stable wall-mounted carbon-dioxide and temperature measurement, with optional humidity, for demanding HVAC and building-automation applications.
The Vaisala HMP4 provides high-accuracy humidity and temperature measurement in compressed air, breathing air, industrial gases, vacuum systems and other processes operating at pressures up to 100 bar.
The Vaisala HMP5 provides high-accuracy humidity and temperature measurement in ovens, dryers, kilns and other processes operating at temperatures up to +180 °C.
The Vaisala HMM170 provides accurate and stable humidity and temperature measurement for demanding environmental chambers, including vacuum and pressurised applications.
The Vaisala HMP60 is a compact, durable and cost-effective humidity and temperature probe for equipment integration, data loggers, incubators, glove boxes, greenhouses and environmental monitoring systems.
It provides 0–100% RH and −40 °C to +60 °C measurement ranges, low power consumption, interchangeable Vaisala INTERCAP sensor and optional Modbus RTU communication.
The Vaisala HMX110 Series provides accurate humidity and temperature measurement for demanding indoor, duct and outdoor HVAC applications.
The Vaisala HMP1 is a high-accuracy, interchangeable humidity and temperature probe for indoor spaces. It connects directly to an Indigo200 or Indigo300 transmitter to create a compact wall-mounted measurement system.
