Rotronic Hygrolog HL-20D-SET1 Humidity & Temperature Measurement Data Logger (Portable)

Rotronic Hygrolog HL-20D-SET1 Humidity & Temperature Measurement Data Logger (Portable)

Rotronic Hygrolog HL-20D-SET1 Humidity & Temperature Measurement Data Logger

Rotronic Hygrolog HL-20D-SET1 is a compact data logger for the measurement of humidity and temperature offering high precision and reliability.

The Hygrolog HL-20D-SET1 is deployable in a wide range of industries and applications and due to the integrated batteries, the data logger can work completely independently offering maximum flexibility.

Typical applications and industries include warehouses, factory halls, museums, office buildings, clean rooms, shipping, libraries, test facilities

Rotronic Hygrolog HL-20D-SET1 Humidity & Temperature Measurement data logger – Product Benefits

Optional display 

  • Display of data on a clear, backlit graphic display
  • Battery charge indicator
  • Display of measured and calculated data
  • Function key to start and stop logging
  • Display resolution to 2 decimal places

Data logging function

  • Logs up to 20,000 value pairs, relative humidity and temperature provided by a single HygroClip2 probe
  • Each record is date and time stamped (real-time clock)
  • Adjustable log interval
  • Two data recording modes: (start-stop or loop)

Alarm Function

  • The visible alarm can be programmed for the Rotronic HL20 and can detect the following:
    • Out-of-limits value (defi ned with HW4 software)
    • Communication loss with the probe
    • Sensor failure and sensor drift

Rotronic HL-20D-SET1

Key user functions of the Rotronic Hygrolog HL-20D-SET1 humidity and temperature data logger include:

  • Highest accuracy at 0.8 %RH and 0.3 ˚C
  • Outstanding long term stability
  • 20,000 data point memory with date & time stamps
  • Programmable alarm limits
  • Programmable recording intervals
  • Psychrometric calculations of dew and frost point values available
  • FDA 21 CFR Part 11 / GAMP 4 compliant
  • UART interface
  • Long battery life

The set consists of:

  • HL-20D
  • Battery
  • HW4-LITE software
  • Cable AC3006

Rotronic HYGROlog HL-20D-SET1 Humidity And Temperature Transmitter

Product Specifications

Dimensions130 x 72 x 32 mm
Operating Range-10…60 °C / 0…100 %rh
Accuracy 23 ±5 °C±0.8 %rh @ 10…60 %rh / ±0.3 K
±1.3 %rh @ 60…100 %rh / ±0.3 K
Measuring Range With Probe-10…60 °C / 0…100 %rh
Power Supply3x AA (1.5 V) alkali battery
Long-Term Stability<1 %rh / year
Response Time T 633 min. (typically)
Psychrometric CalculationsDew or frost point
Measurement Interval5 sec. to 1 hour in 5 sec. increments
Memory Size20000 data values (%rh/°C, Date, Time)
Status Indicator LED5 sec.: Green flash when recording data, red flash for out-of-limit value or logger problem
Communication InterfacesMini USB (UART)
Enclosure MaterialABS
IP Protection RatingIP40
FDA/GAMP CompatibilityFDA 21 CFR Part 11 and GAMP compatible


The pharmaceutical industry is one of the largest users of humidity measurement equipment. Most drugs are sensitive to variations in humidity and moisture levels, so these need to be considered and controlled using measurement instruments, probes and sensors for the final products to be consistent in quality and performance.

Humidity Measurement Applications

Humidity instruments are used to both control (transmitters) and monitor (transmitters or data loggers) these conditions during “accelerated conditions” drug testing.

Production machines, driers, tableters, and coaters are all sensitive to humidity – quality control requires machine monitoring, area monitoring and final product Equilibrium Relative Humidity (ERH) measurement.

Clean room environments are humidity critical – environmental monitoring system (EMS) and measurement is validated to conform with regulatory requirements.


View the current Rotronic catalogue :


T&D distribute Rotronic probes, instruments, transmitters, data loggers, indicators and sensors for the measurement of dew point, flow, air velocity, process pressure, carbon dioxide and temperature. Click an icon for further information…..


Rotronic - Dew Point Measurement

Low Dew Point

Rotronic - Flow Measurement

Flow & Air Velocity

Rotronic - Process Pressure Measurement

Process Pressure

Rotronic - CO2 Measurement

Carbon Dioxide

Rotronic - Temperature Measurement


➡ Did you know? T&D supply VEGA process instrumentation for pressure, level and point level (switching) measurement

Data Sheets