The most versatile humidity, temperature, and barometric pressure probe on the market

The Evvos RHTP probe combines meteorological grade sensors for relative humidity, air temperature, and barometric pressure measurements. It is designed to provide high-quality environmental data, real-time measurements, and calculation of multiple derivative parameters.

Accurate, Rugged, Wide Temp Range

Ideal for long-term, unattended remote monitoring.

Buy for € 239
Relative humidity, temperature, and barometric pressure probe % °C hPa Filter Enclosure Connector
Relative humidity, temperature, and barometric pressure sensor


SDI-12 Quickstart Guide
User’s Manual (SDI-12 Interface)
Buy Probe & Shield for € 295

ERHTP Probe Parameters

Relative humidity
Air Temperature
Barometric pressure

Dew point
Absolute humidity
Wet-bulb temperature

Vapour pressure
Saturated vapour pressure
Speed of sound in air

Heat index
Mixing ratio
Specific enthalpy

Boiling point of water
Water activity in air
Atmospheric pressure at sea level


  • Stainless steel enclosure and filter cap engineered to protect sensing elements
  • Internal electronics sealed in raisin
  • Heater used at very high humidity levels for removing condensated water drops on humidity sensor
  • Heater control command set (aXH!) to easily control heating/cooling cycles
  • Statistics control command set (aXS!) to manage continuously accumulating statistical data for all evnvironmental parameters
  • See level pressure configuration command set (aXP!)
  • User calibration command set to manage individual, multipoint calibration for each primary parameter
  • Multiple electrical interfacing options – SDI-12 (v.1.4)
    • Optional RS-485 (Modbus – available in Nov-2022)
    • UART, USB (available in H1/2023)
  • Low-power consumption suitable for battery-powered applications
  • Earthing – probe’s metal casing internally connected to GND
  • UV-protected and oil-resistant flexible cable

Evvos Lab Weather Station

Click image for live weather data

ERHTP Dashboard


  • Environmental monitoring

  • Weather forecasting solutions
  • Industrial data acquisition
  • Cold chain and HVAC applications
  • Precision agriculture/farming

  • Internet of Things

ERHTP is a robust, high-accuracy, digital probe. It measures multiple environmental parameters. Due to its low power consumption, versatile electrical interfacing options, and wide power supply range, the probe is compatible with a variety of battery-operated dataloggers and industrial data acquisition systems. A stainless-steel enclosure in combination with weatherproof electronic circuitries, and durable cable, ensure proper long-term operation even in harsh outdoor and industrial conditions. All primary parameters are sensed by physical sensors. The secondary parameters are calculated, based on values measured by the probe’s physical sensors. The enhanced accuracy version of the probe provides high accuracy measurement of relative humidity, and air temperature without user-defined calibration.


Probe ConnectorPin Function
ERHTP Connector

ERHTP Connector

Pin 1 – System power supply (Vin)

Pin 2 – System ground (GND)

Pin 3 – Auxilary (AUX)

Pin 4  – DATA 1

Pin 5 – DATA 2

M12-Sensor cable included. The 1.5 m., 5-position, PUR halogen-free, black-gray RAL 7021, free cable end, on socket straight M-12, A-coded sensor cable suitable for RHTP versions with SDI-12, single-wire, and UART interfaces.

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