Humidity and Temperature Transmitter (Meteorological Grade) HMP155 Humidity and Temperature Transmitter (Meteorological Grade) HMP155
Humidity and Temperature Transmitter (Meteorological Grade) HMP155
Humidity and Temperature Transmitter (Meteorological Grade) HMP155
Humidity and Temperature Transmitter (Meteorological Grade) HMP155

Vaisala HMP155 Meteorological Humidity and Temperature Probe

Vaisala HMP155 Meteorological Humidity and Temperature Probe

The Vaisala HMP155 provides stable humidity and temperature measurement for automatic weather stations, road-weather systems, airports, research sites and demanding outdoor monitoring.

  • Relative-humidity measurement from 0 to 100 %RH
  • Operating range from −80 to +60 °C
  • HMP155A with two analogue voltage outputs
  • HMP155D with RH voltage output and passive four-wire Pt100 temperature
  • HMP155E with RS-485 digital output
  • Optional warmed probe, chemical purge and additional temperature sensor

Vaisala HMP155 for Meteorological Humidity and Temperature Measurement

The Vaisala HUMICAP® HMP155 is designed for accurate and stable outdoor humidity and temperature measurement. Its weather-resistant probe construction, protective filter options and long-term measurement stability make it suitable for professional meteorology and other exposed environmental-monitoring locations.

Typical installations include automatic weather stations, airport observation systems, road-weather stations, agricultural research, hydrology sites, environmental-monitoring networks and industrial locations requiring meteorological-grade outdoor measurements.

Choose the Correct HMP155 Model

ModelHumidity outputTemperature outputRecommended use
HMP155A Analogue voltage Analogue voltage Data loggers and weather stations requiring two active voltage signals
HMP155D Analogue voltage Passive four-wire Pt100 Systems that read RH as voltage and temperature directly from a precision resistance input
HMP155E RS-485 digital RS-485 digital Digital data-acquisition systems requiring serial measurement data

Selection point: all HMP155 models have an RS-485 interface for service use, but HMP155E is the model intended to provide RS-485 as its measurement output. Select the complete model and output configuration according to the receiving data logger or weather-station controller.

HMP155 Measurement Performance

Measurement specificationPerformance
Relative-humidity range 0 to 100 %RH
RH accuracy at +15 to +25 °C ±1 %RH from 0 to 90 %RH; ±1.7 %RH from 90 to 100 %RH
Factory-calibration uncertainty at +20 °C ±0.6 %RH from 0 to 40 %RH; ±1.0 %RH from 40 to 95 %RH
Humidity sensor HUMICAP® R2, HUMICAP® 180R or configuration-dependent equivalent; composite versions for purge or warming
Temperature observation range −80 to +60 °C
Temperature sensor Pt100 RTD, Class F0.1 according to IEC 60751
Operating voltage 7 to 28 V DC; required minimum depends on output and heating options
Ingress protection IP66
Probe dimensions Approximately 279 × 40 mm

Warmed Probe for High-Humidity Conditions

Fog, rain, heavy dew and near-saturated air can wet an unheated humidity sensor and temporarily prevent it from representing the surrounding atmosphere. The optional warmed-probe function keeps the sensor head above the ambient dew-point temperature, reducing the risk of condensation on the sensing element.

Because warming changes the temperature at the humidity sensor, accurate ambient relative humidity is calculated using a separate temperature measurement. Select the warmed-probe and additional-temperature-sensor arrangement together rather than treating probe heating as an independent accessory.

Chemical Purge and Sensor Protection

Optional chemical purge periodically heats the humidity sensor to reduce the effect of certain chemical contaminants. This is useful where long-term stability may be challenged by airborne chemicals, but it does not replace correct siting, filter selection, inspection or calibration.

A sintered PTFE filter provides strong protection against water, dust and dirt. A membrane filter can provide faster response where the application and exposure conditions allow it. Filter condition should be checked during scheduled weather-station maintenance.

Selecting a Radiation Shield

Installation optionPurposeSelection guidance
DTR503 Natural-aspiration radiation shield for HMP155 installations Common choice for automatic weather stations and exposed monitoring sites
DTR13 Compact radiation shield for compatible probe installations Use where its mounting arrangement and measurement requirements are suitable
Stevenson screen Traditional naturally ventilated instrument enclosure Suitable where the observation standard or existing station design requires it
DTR502 with additional-temperature-probe kit Shielding of the separate temperature sensor Used with applicable warmed-probe configurations requiring independent ambient temperature

Radiation shielding is essential for representative outdoor temperature and humidity measurement. The shield must protect the sensor from precipitation and direct or reflected solar radiation while allowing sufficient airflow around the probe.

HMP155 or an Industrial HMP Probe?

Selection pointHMP155Industrial HMP probe
Primary role Meteorological and exposed outdoor measurement Industrial process, duct, chamber or pipeline measurement
Typical installation Radiation shield, weather station or environmental-monitoring mast Process fitting, duct kit, chamber or Indigo transmitter
Temperature environment Outdoor operation down to −80 °C, up to +60 °C Application-dependent probes covering general, high-temperature, high-humidity and pressurised processes
Outputs Voltage, passive Pt100 or RS-485 according to HMP155 model Standalone Modbus RTU or connection to an Indigo transmitter, depending on probe
High-humidity strategy Optional warmed probe with additional ambient-temperature measurement Vaisala HMP7 for continuously humid industrial processes

Maintenance and Calibration

Inspect the radiation shield, filter and probe for contamination, insects, salt deposits and physical damage. Clean or replace affected components according to Vaisala instructions and the environmental exposure at the site.

Calibration frequency should reflect the required measurement uncertainty, site conditions, maintenance history and applicable quality procedures. Keep calibration certificates and adjustment records linked to the probe serial number.

Vaisala HMP155 Supplier and Technical Support in Malaysia

Seacom Process Instruments supplies and supports the Vaisala HMP155 meteorological humidity and temperature probe in Malaysia for automatic weather stations, airports, road-weather systems, research sites, plantations and environmental-monitoring networks.

Our team can assist with choosing HMP155A, HMP155D or HMP155E, selecting warmed-probe and chemical-purge options, matching the radiation shield, reviewing power and output requirements, planning installation and arranging calibration.

Contact Seacom with your temperature and humidity range, required output, data-logger input, site exposure, shield preference, cable length and calibration requirements so we can recommend a suitable HMP155 configuration.

Download

  HMP155 Catalogue   (240.68k)


Specific References

12 other products in the same category:

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Vaisala HMP3

Vaisala HMP3 General-Purpose Humidity and Temperature Probe

Vaisala HMP3 General-Purpose Humidity and Temperature Probe

The Vaisala HMP3 is a high-accuracy, field-maintainable probe for industrial HVAC, air-handling units, cleanrooms, paint booths and environmental chambers.

  • Humidity accuracy up to ±0.8% RH
  • Temperature measurement from −40 to +120 °C
  • Field-replaceable filter and HUMICAP sensor option
  • Standalone Modbus RTU or Vaisala Indigo transmitter operation
Vaisala HMT330 Humidity and Temperature Transmitter Series – Discontinued

Vaisala HMT330 Humidity and Temperature Transmitter Series – Discontinued

Vaisala HMT330 Humidity and Temperature Transmitter Series

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.

  • HMT331 wall mounting → HMP1 with Indigo500
  • HMT333 ducts and tight spaces → HMP3 or HMP9 with Indigo500
  • HMT334 high pressure and vacuum → HMP4 with Indigo500
  • HMT335 high temperature → HMP5 with Indigo500
  • HMT337 high humidity → HMP7 with Indigo500
  • HMT338 pressurised pipelines → HMP8 with Indigo500
Vaisala HMM105 Digital Humidity Module for Environmental Chambers

Vaisala HMM105 Digital Humidity Module for Environmental Chambers

Vaisala HMM105 Digital Humidity Module

The Vaisala HMM105 provides reliable humidity measurement for integration into environmental chambers, incubators and OEM equipment.

  • 0–100% RH measurement range
  • I2C output for relative humidity or dew point
  • Detachable 12 mm probe with 300 mm flexible cable
  • Probe withstands +180 °C continuously and +200 °C temporarily
Vaisala Origo10

Vaisala Trasmitter Origo10 Series

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.

Vaisala Humidity And Temperature Transmitter XMP10

Vaisala XMP10 Series Humidity and Temperature Probes

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.

Indigo200 Series Transmitters for Vaisala smart probes for Vaisala Smart Probes

Vaisala Indigo200 Series Transmitters

Vaisala Indigo200 Series Transmitters

The Vaisala Indigo200 Series is the standard transmitter platform for one interchangeable Indigo-compatible smart probe, providing local display and practical automation-system connectivity.

  • Indigo201 with three analog outputs and two relays
  • Indigo202 with Modbus RTU and two relays
  • Colour display with numerical and graphical views
  • IP65 enclosure for industrial measurement applications
Vaisala XMW85 CO2, Humidity and Temperature Modbus Transmitter

Vaisala XMW85 CO2, Humidity and Temperature Modbus Transmitter

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.

Vaisala HMW90 High-Accuracy Humidity and Temperature Transmitter

Vaisala HMW90 High-Accuracy Humidity and Temperature Transmitter

Vaisala HMW90 High-Accuracy Humidity and Temperature Transmitter

The Vaisala HMW90 Series provides high-accuracy humidity and temperature measurement for demanding indoor HVAC and controlled-environment applications.

  • Humidity accuracy up to ±1.7% RH
  • Analog or Modbus RTU output models
  • Optional display and configurable relay
  • Replaceable measurement module with calibration certificate
Vaisala HMT120 and HMT130 Transmitters – Are Being Replaced by Origo10

Vaisala HMT120 and HMT130 Transmitters – Are Being Replaced by Origo10

Vaisala HMT120 and HMT130 Humidity and Temperature Transmitters

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.

  • Humidity accuracy up to ±1.5% RH
  • HMT120 loop-powered 4–20 mA output
  • HMT130 voltage outputs, RS-485 and relay
  • Interchangeable fixed or remote measurement probe
  • Origo10 recommended for new installations
Vaisala HMP7

Vaisala HMP7 High-Humidity and Temperature Probe

Vaisala HMP7 High-Humidity and Temperature Probe

The Vaisala HMP7 is designed for continuously humid, rapidly changing and near-condensing environments. Probe heating helps prevent condensation while maintaining reliable process measurement.

  • Humidity accuracy up to ±0.8% RH
  • Probe heating for condensation prevention
  • −70 to +180 °C probe-head measurement range
  • Standalone Modbus RTU or Vaisala Indigo transmitter operation
Vaisala Indigo510 Indigo520 Malaysia

Vaisala Indigo510 and Indigo520 Flagship Transmitters

Vaisala Indigo510 and Indigo520 Flagship Transmitters

The Vaisala Indigo500 Series provides flagship industrial measurement integration: choose Indigo510 for a simplified single-probe system or Indigo520 for full dual-probe capability.

  • Indigo510: one probe and two isolated analog outputs
  • Indigo520: two probes, four isolated outputs and two relays
  • Ethernet web interface and Modbus TCP communication
  • Rugged IP66 and NEMA 4 metal enclosure
Biogas Methane, Carbon Dioxide and Humidity Multigas Probe MGP261

Biogas Methane, Carbon Dioxide and Humidity Multigas Probe MGP261

for smart control of biogas quality

Get more value out of waste by improved decision-making, and by reducing your operating costs. Vaisala CARBOCAP® MGP261 Multigas Probe for Methane, Carbon Dioxide and Humidity helps in improving your process and in protecting the Combined Heat and Power (CHP) engine. The MGP261 probe is compact in size, Ex certified, and can be installed directly into the gas line without the need for sample treatment.

>The measurement probe is suitable for applications such as anaerobic digestion of landfill, industrial and municipal waste, wastewater treatment, CHP engine monitoring, as well as active carbon filter monitoring.

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