Extech Instruments HT30 User Manual page 4

Operation
BASIC USE
1. Press the power button to switch ON or OFF.
2. Slide the protective cover down to expose sensors when taking
readings. Slide the cover up to protect sensors when storing.
3. Press MODE to select mode of operation: Wet Bulb Globe tem-
perature (WBGT), air temperature (TA), Black Globe tempera-
ture (TG), relative humidity (RH).
4. Press MODE and NEXT simultaneously to toggle the tempera-
ture units.
5. Long press MODE to toggle indoor (IN) and outdoor (OUT) use.
For outdoor use, direct sun exposure modifies the reading.
6. Read the measurement on the display. To better interpret the
readings, refer to the Appendices section.
ALARM
The HT30 features a heat stress alarm. The alarm beeper sounds
when the a WBGT reading exceeds the alarm set point. The set
point range is 68.0 to 99.0℉ (20.0 to 37.2℃).
1. Switch OFF the meter and then long press the SET button for 2
seconds to access the alarm set point, the most significant digit
will be blinking.
2. Use the up arrow button to adjust the digit value.
3. Short press the NEXT button to select the next digit for editing.
4. When all digits are set, long press the NEXT button to return to
normal operation.
5. When the WBGT alarm set point is exceeded, the beeper will
sound. To silence the beeper, switch OFF the HT30.
AUTO POWER OFF (APO)
APO automatically switches OFF the meter after approximately 20
minutes. To disable APO, switch OFF the meter and then long
press the SET and MODE buttons for 2 seconds. The display will
switch ON and briefly show "n", indicating that APO has been dis-
abled. Note that APO will be enabled again (default) the next time
the meter power is cycled.
PC INTERFACE
The HT30 includes a 3.5 mm female mono jack on the right side of
the meter. Order the optional PC Windows® software and cable
(3.5 mm to USB) using part number 407752. You can also down-
load the software from the website, address below. The software
#NAS100230; r. AA/99106/99106; en-US
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