Rotronic HL-1D Temperature and Humidity Data Logger

The Rotronic HL-1D is a reusable temperature and humidity logger that records temperature and relative humidity from -30 to +70°C. Rotronic specifies the HL-1D at ±0.3°C (-30 to +70°C), ±0.5°C otherwise accuracy with 0.1°C resolution. On the HL-1D, humidity is measured from 0 to 100 %RH at ±2 %RH (10 to 90 %RH at 23 ±5°C), ±5 %RH otherwise. Down to -30°C, the HL-1D covers 2–8°C fridges as well as -20°C freezers.

Memory holds 32,000 readings with an interval settable from 30 s to 24 h, about 333 days of logging at 15-minute steps. Rotronic lists the maximum runtime of the HL-1D as >3 years at 60 min interval. Data from the HL-1D comes off over USB in HW4 V3.4.1 or later. Alarm options on the HL-1D are high/low.

Physically, the HL-1D has LCD, 2 lines; 2 LEDs display and IP67 protection. Listed approvals for the HL-1D: EN 12830. For calibration, the HL-1D comes with: function and calibration certificate included. In practice the Rotronic HL-1D fits storage areas where humidity affects quality, 2–8°C or frozen.