This document is the instruction manual for HI 8564 and HI93640 portable thermo-hygrometers.
The HI8564 and HI93640 are portable thermo-hygrometers designed to provide high-precision readings for relative humidity (RH) and temperature. The HI8564 is supplied with an external RH probe (HI70601/2), while the HI93640 features a built-in sintered cap probe. Both instruments measure RH from 5% to 95% and temperature from 0°C to 60°C (32°F to 140°F) with a resolution of 0.1% RH and 0.1°C/1°F.
| Temperature Range | 0°C to 60°C (32°F to 140°F) |
|---|---|
| Resolution | 0.1% RH, 0.1°C / 1°F |
| Accuracy | ±2% RH, ±0.4°C / ±1°F |
| Battery Type | 1 x 9V |
| Battery Life | approx. 100 hours |
It is generally recommended to have all hygrometers recalibrated at least once a year.
The "V" symbol is displayed on the LCD to warn the user.
No, the RH probe sensor must never come into contact with water or other liquids.