General Tools and Instruments HT50 v.1 - Manual (Page 19)

of the STO button toggle displayed temperature readings
between °C and °F.
When the LCD is displaying a temperature or humidity
reading, it also gives an indication if the reading is outside the
“acceptable” range of readings for that parameter—
assuming that high and/or low alarm setpoints were entered
during the Setup procedure. If an “up” arrow appears at the
left of the reading (see Fig. 1b on p. 7), the measured value of
that parameter is higher than its high alarm setpoint. If a
“down” arrow appears at the left of the reading, it is lower
than the low alarm setpoint for that parameter.
SPECIFICATIONS
Ambient Temperature -4° to 158°F (-20° to 70°C)
Measurement Range
Ambient Temperature ±0.7°F (0.4°C)
Measurement Accuracy
Ambient Temperature Measurement ±0.2°F (0.1°C)
Resolution and Repeatability
Relative Humidity (RH) 10 to 90%
Measurement Range
RH Measurement Accuracy ±3%
RH Measurement Resolution ±0.1%
and Repeatability
IR (Surface) Temperature -4° to 482°F (-20° to 250°C)
Measurement Range
IR Temperature ±5°F (3°C)
Measurement Accuracy
19