The Vaisala HMT120 and HMT130 provide accurate, stable humidity and temperature measurement for cleanrooms, laboratories, data centres and demanding HVAC applications.
Product transition: HMT120/HMT130 are expected to be phased out. For new projects, the Vaisala Origo10 is the recommended replacement platform.
The Vaisala HUMICAP HMT120 and HMT130 are high-accuracy humidity and temperature transmitters designed for cleanrooms, laboratories, data centres, museums and demanding HVAC or light-industrial applications.
Both models use an interchangeable measurement probe, allowing the probe to be removed and replaced without readjusting the transmitter. This minimises system downtime and makes it easier to maintain measurement traceability.
The main difference is the electrical interface. The HMT120 is a two-wire, loop-powered transmitter with 4–20 mA outputs. The HMT130 is a three-wire transmitter offering configurable voltage outputs, non-isolated RS-485 communication and a relay.
The HMT120 and HMT130 are approaching the end of their product lifecycle and are expected to be phased out within approximately one to two years. They remain relevant for existing installations, specified replacements and projects that require compatibility with an installed HMT120/HMT130 system.
For new cleanroom, laboratory, data-centre and demanding HVAC projects, the Vaisala Origo10 is the recommended successor. Origo10 retains the modular transmitter-and-probe approach while providing a newer platform for building-management and automation integration.
| Project Situation | Recommended Approach |
|---|---|
| New project or new system specification | Select Vaisala Origo10 as the preferred replacement platform |
| Existing HMT120/HMT130 installation | Review like-for-like replacement availability and the future migration plan |
| Immediate replacement of a failed transmitter | Confirm HMT120/HMT130 availability, probe compatibility and output requirements with Seacom |
| System expansion | Compare extending the existing platform with beginning a controlled transition to Origo10 |
| Feature | HMT120 | HMT130 |
|---|---|---|
| Wiring | Two-wire, loop powered | Three-wire |
| Primary Output | 4–20 mA current output | 0–1 V, 0–5 V, 0–10 V or user-defined voltage output between 0–10 V |
| Serial Interface | Service interface for configuration and calibration | Non-isolated RS-485 |
| Relay | Not available | One relay, maximum 50 V DC and 200 mA |
| Supply | 10–30 V DC at zero loop resistance | 10–35 V DC or 24 V AC ±20%; 15–35 V DC when using 0–10 V output |
| Recommended Use | Conventional 4–20 mA monitoring, PLC and building-automation inputs | Voltage-output systems, serial communication and local relay applications |
| Probe | Construction | Operating Range | Recommended Application |
|---|---|---|---|
| HMP110 | Stainless-steel humidity and temperature probe with Vaisala HUMICAP sensor | -40 °C to +80 °C | Demanding cleanroom, industrial, outdoor and remote-probe applications |
| HMP113 | Lightweight PC/ABS humidity and temperature probe with Vaisala HUMICAP sensor | -40 °C to +60 °C | General indoor and fast-response HVAC applications |
| HMP110REF | Constant-output reference probe | Provides fixed humidity and temperature values | Checking the monitoring system, transmitter input and signal-transfer path |
| Specification | Performance |
|---|---|
| Measurement Range | 0–100% RH |
| Accuracy at 0 °C to +40 °C, 0–90% RH | ±1.5% RH |
| Accuracy at 0 °C to +40 °C, 90–100% RH | ±2.5% RH |
| Accuracy Outside the Central Temperature Range, 0–90% RH | ±3% RH within the applicable probe operating range |
| Accuracy Outside the Central Temperature Range, 90–100% RH | ±4% RH within the applicable probe operating range |
| Factory Calibration Uncertainty at +20 °C, 0–90% RH | ±1.1% RH |
| Factory Calibration Uncertainty at +20 °C, 90–100% RH | ±1.8% RH |
| Typical HVAC Stability | ±0.5% RH per year |
| Standard Humidity Sensor | Vaisala HUMICAP 180R |
| Specification | HMP110 | HMP113 |
|---|---|---|
| Measurement Range | -40 °C to +80 °C | -40 °C to +60 °C |
| Accuracy at +15 °C to +25 °C | ±0.1 °C | ±0.1 °C |
| Accuracy at 0 °C to +15 °C and +25 °C to +40 °C | ±0.15 °C | ±0.15 °C |
| Accuracy Outside 0 °C to +40 °C | ±0.4 °C within the probe range | ±0.4 °C within the probe range |
Depending on the ordered configuration, HMT120 and HMT130 can output or display several humidity-related parameters.
| Parameter | Application |
|---|---|
| Relative Humidity | Environmental control and routine cleanroom monitoring |
| Dew Point or Frost Point | Condensation-risk and low-temperature moisture assessment |
| Wet-Bulb Temperature | Psychrometric and evaporative-cooling calculations |
| Enthalpy | HVAC energy and air-treatment analysis |
| Absolute Humidity | Water-vapour mass per unit volume |
| Mixing Ratio | Water-vapour mass relative to dry air |
| Vapour Pressure | Water-vapour partial-pressure assessment |
| Saturation Vapour Pressure | Humidity calculations at the measured temperature |
| Feature | Specification |
|---|---|
| Transmitter Type | Two-wire, loop powered |
| Current Output | 4–20 mA |
| External Loop Voltage at 0 Ω | 10–30 V DC |
| External Loop Voltage Below 500 Ω | 20–30 V DC |
| Feature | Specification |
|---|---|
| Transmitter Type | Three-wire |
| Voltage Outputs | 0–1 V, 0–5 V, 0–10 V or user-defined between 0–10 V |
| Minimum Output Resistance | 1 kΩ |
| Serial Interface | RS-485, non-isolated |
| Relay | One relay, maximum 50 V DC and 200 mA |
| Supply Voltage | 10–35 V DC; 15–35 V DC for 0–10 V output; or 24 V AC ±20% |
| Current Consumption at 24 V DC | 8 mA; 15 mA with relay closed |
The HMT120 and HMT130 enclosure is designed for cleanroom use. Its smooth external surface is easy to wipe, the enclosure material tolerates common cleaning agents, and wiring can enter through the rear wall to minimise exposed cabling.
HMT120 and HMT130 are also suitable for data centres and other facilities requiring dependable room, duct or remote humidity and temperature measurements.
For data-centre planning guidance, see our Vaisala Data Centre Environmental Monitoring Guide.
Remote-probe models can be adapted for outdoor or duct measurement using the correct Vaisala accessories.
| Specification | Value |
|---|---|
| Transmitter Protection | IP65 |
| Transmitter Operating Temperature without Display | -40 °C to +60 °C |
| Transmitter Operating Temperature with Display | -20 °C to +60 °C |
| Storage Temperature | -50 °C to +70 °C |
| Weight | Approximately 270 g |
| Optional Display | 128 × 64 pixel monochrome graphical display without backlight |
| Transmitter Housing | PBT plastic |
| Terminal Wire Size | 0.5–1.5 mm² or AWG 20–15 |
| Probe Interface | Four-pin female M8 panel connector |
| Requirement | Recommended Configuration |
|---|---|
| Loop-powered 4–20 mA output | HMT120 |
| Voltage output or relay | HMT130 |
| Local measurement display | HMT120 or HMT130 with optional display |
| Rugged stainless-steel probe | HMP110 probe |
| Lightweight fast-response indoor probe | HMP113 probe |
| Restricted or higher-temperature measuring point | Remote HMP110 probe with suitable cable and mounting accessory |
| System signal-path verification | HMP110REF constant-output probe |
| New platform evaluation | Ask Seacom to compare HMT120/HMT130 with the newer Vaisala Origo10 platform |
Seacom Process Instruments supplies and supports the Vaisala HMT120 and HMT130 humidity and temperature transmitters in Malaysia.
Our team can assist with existing-system replacement requirements, model selection, probe type, output signal, display option, remote-probe cable, installation accessories, calibration planning and migration to the Vaisala Origo10 platform.
Contact Seacom with your required measurement range, output type, probe location, cable distance and environmental conditions for a suitable configuration.
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 HMT330 Series was a flagship industrial transmitter platform for humidity, temperature and calculated moisture parameters. It is discontinued and replaced by an Indigo500 transmitter with the HMP probe selected for the application.
The Vaisala HMT140 Wi-Fi Data Logger has been discontinued and is no longer recommended for new monitoring systems.
The Vaisala HMP3 is a high-accuracy, field-maintainable probe for industrial HVAC, air-handling units, cleanrooms, paint booths and environmental chambers.
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 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 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 HMM100 provides reliable humidity measurement and a configurable analog output for integration into environmental chambers and OEM equipment.
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 Indigo520 Supervisor manages up to 100 compatible compact humidity and temperature probes through one host unit. It provides local visibility for the maintenance team and Modbus TCP communication for data centre BMS integration.
Expected availability: early 2027. Enquire with Seacom for configuration and delivery confirmation.
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 HMT370EX provides intrinsically safe humidity and temperature measurement with HMP-series probes. The new DMP370 configuration combines the HMT370EX transmitter with a DMP37X DRYCAP® probe for low-dew-point measurement in hazardous locations.
DMP370 availability: Vaisala plans first deliveries for Q1 2027. Contact Seacom for configuration and project lead time.
The Vaisala HMM170 provides accurate and stable humidity and temperature measurement for demanding environmental chambers, including vacuum and pressurised 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 HMP9 combines a miniature 5 mm probe head with fast-response, high-accuracy humidity and temperature measurement for tight spaces and rapidly changing environments.
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 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.
