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  • HF8
  • Usually ships in 4-6 weeks



  • Highest accuracy at 0.8% rh and 0.1°C
  • Outstanding long-term stability and chemical resistance
  • Widest temperature measuring range at -100 to 200°C
  • Two interchangeable HygroClip digital or analog probe inputs
  • 10,000 point datalogging with time stamp and battery backup
  • Up to 4 programmable analog outputs available
  • Digital output options
  • Multiple alarm relays
  • Audible and visual alarms
  • Galvanically isolated power supply


The Rotronic HygroFlex8 is an industrial humidity and temperature transmitter that provides problem-free, accurate humidity measurement resulting from the most stable sensor in the industry. Featuring AirChip3000 digital technology and compatible with HygroClip digital probe technology, the HygroFlex8 has practically no maintenance downtime. When it's time for a scheduled calibration, HygroFlex8 transmitters provide superb precision and state-of-the-art functionality, taking humidity and temperature measurement to a whole new level of performance and reliability with 0.8% rh and < 0.1°C accuracy.

The Rotronic HF8 has four freely selectable and scalable analog outputs. Optional digital outputs allow integration on a network via an Ethernet or RS-485 connection. The combined digital and analog output signals, allow controlling and steering a device with one transmitter. The Rotronic HygroFlex8 humidity temperature transmitter logs up to 10,000 value pairs, relative humidity and temperature provided by a single HygroClip2 probe. Both probe inputs can be logged at the same time and each record is date and time stamped.

The Rotronic HygroFlex8 humidity temperature transmitter can have up to 4 relay outputs. Each relay can be programmed individually and each relay can be set to control any measured or calculated parameter. A visible and audible alarm can be programmed when the HF8 detects the following: Out-of-limits value (defined with the HW4) for each probe input, communication loss with the probe and an impaired rh sensor or major sensor failure.

The Rotronic HygroFlex8 humidity temperature transmitter can be used with a choice of probes. The HF8 is compatible with all HygroClip2 Probes and allows for the connection of two analog probes. Changing of HygroClip2 probes is easy and requires no further adjustment. Probes can be ‘hot swapped' in seconds with a calibrated probe without loss of measurement accuracy. The use of probe simulators allows for easy process validation.

The Rotronic HygroFlex8 humidity temperature transmitter is available with an optional display. The clear, backlit graphic display is easy to read and the simple menu navigation provides fast access to all the available information. Other display features include trend indication of values; display resolution to 2 decimal places; calculation and display of delta value between the two probes and three programmable display formats.

Rotronic HygroFlex8 Humidity Temperature Transmitter Specifications
Device Type Humidity temperature transmitter with analog output signals, relay outputs. Optional digital interface: Ethernet, RS-485
Circuit Type 3-wire
Probe Inputs 2 (digital or analog)
Digital Probe HygroClip2
Analog Probe Supply voltage to probe: 5 VDC Max
Probe signal range: 0 to 3.3 VC configurable measuring range and measurement unit
Probe Type All HC2 probes (digital)
Accuracy ±0.8% rh/0.1°C (typically value), probe dependent
Measurement Range -100 to 200°C / 0 to 100 %rh, probe dependent
Psychrometric Calculations Dew point (Dp) above and below freezing
Frost point (Fp) below freezing and dew point above freezing
Wet bulb temperature (Tw) , Enthalpy (H)
Vapor concentration (Dv) , Specific humidity (Q)
Mixing ratio by weight (R), Vapor concentration at saturation (Dvs)
Vapor partial pressure (E), Vapor saturation pressure (Ew)
Analog Output Analog output signals, scalable by user: 0 to 20 mA, 4 to 20 mA, 0 to 1 V, 0 to 5 V, 0 to 10 V
Interface RS-485 and analog output Ethernet (wired); RS-485 and analog output Ethernet with PoE


Required Components

These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.