Meter Operation - Extech Instruments HT30 User Manual

Meter Operation

1. Press the
2. Slide down the protective sensor cover before taking measurements.
3. Press the MODE/
Index (WBGT), Air Temperature (TA), Black Globe Temperature (TG), or Relative Humidity
(RH). An icon will appear in the display indicating the current selection.
4. To select the preferred temperature unit (°F or °C), simultaneously press and release the

MODE/ and NEXT buttons. The F or C icon will appear in the display.
5. The meter measures WBGT index with (IN) or without (OUT) direct sun exposure. Hold down

the MODE/
appear in the display.
Alarm Setting
The HT30 has a user settable heat stress alarm. The HT30 will emit an audible beep when the heat
stress WBGT reaches the level previously set by the user. The alarm will continue beep until the
measured WBGT temperature falls below the alarm level set by the user, or the meter is turned off.
The setting range is from 68.0 to 99.0°F (20.0 to 37.2°C).
1. To enter the alarm setup mode, hold down the
turning the meter on.
2. The current alarm setting will be displayed with the most significant digit blinking.
3. Use the MODE/
4. To set the next digit, momentarily press the NEXT button.
5. After all of the digits are set, press and hold the NEXT button for 2 seconds to return to the
measuring mode.
NOTE: The OUT icon will appear in the display If the new setting is out of the setting range of the
alarm.
/SET button to power the instrument on/off.

button to select the desired display mode: Wet Bulb Globe Temperature
for more than 1 second to alternate between settings. The IN or OUT icon will

button to increment the digit.
/SET button for more than 2 seconds when
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