The compact data logger for humidity and temperature measurement offers high precision and reliability at a reasonable price. The HL-20 series is easy to use and
deployable in a wide range of applications. Thanks to its integrated batteries, the HL-20 works completely independently and offers its users maximum flexibility.

Warehouses, factory halls, museums, office buildings, clean rooms, shipping, libraries, test facilities

• Highest accuracy at 0.8 %RH and 0.2 ˚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

Dimensions 130 x 72 x 32 mm
Operating range -10…60 °C / 0…100 %rh
Accuracy at 23 ±5 °C ±0.8 %rh @ 10...60 %rh / ±0.3 K
±1.3 %rh @ 60...100 %rh / ±0.3 K
Measuring range with integrated probe -10…60 °C / 0…100 %rh
Power supply / Power consumption 3x AA (1.5 V) alkali battery
Long-term stability <1 %rh / year
Response time t 63 3 min. (typically)
Psychrometric calculations Dew or frost point
Measurement interval 5 sec. to 1 hour in 5 sec. increments
Memory size 20000 data values (%rh/°C, Date, Time)
Status indicator LED 5 sec.: Green flash when recording data, red flash for out-of-limit value or logger problem
Communication interfaces Mini USB (UART)
Enclosure material ABS
IP protection rating IP40
FDA/GAMP compatibility FDA 21 CFR Part 11 and GAMP compatible