Quest Diagnostics QUESTEMP 36 - Manual (Page 3)

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1. UP AND RUNNING
1. Make sure the wet bulb’s wick is clean. Fill the reservoir with distilled
water.
2. Place the QUESTemp in the work area in a safe location approximately 3.5
feet off the ground.
3. Turn the unit ON. If the battery voltage displayed during the power-on
sequence is less than or equal to 6.4 volts, replace or recharge the batteries.
4. Be aware that the sensors require 10 minutes to stabilize to a new
environment.
5. Press the RUN STOP key to begin datalogging.
6. Use the arrow keys to set the display to the desired items.
2. USING THE QUESTEMP
The QUESTemp should be placed at a height of 3.5 feet (1.1m) for standing
individuals or 2 feet (.6m) for seated individuals. Tripod mounting is
recommended to get the unit away from anything that might block radiant heat or
airflow. A 1/4"x20 threaded bushing on the bottom of the instrument allows
mounting to a standard photographic tripod. Do not stand close to the unit during
sampling.
Make sure that the wet bulb reservoir is filled with distilled water and that the
cotton wick is clean and fully wetted. After adding water or placing the unit in a
new environment, allow ten minutes for the globe and wet bulb readings to
stabilize.
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3. MEASUREMENTS
The QUESTemp °36 data logging area heat stress monitor measures four
parameters: ambient or dry bulb temperature (DB), natural wet bulb
temperature (WB), globe temperature (G), and relative humidity (RH).
It computes the Wet Bulb Globe Temperature (WBGT), stay times for three
possible indices, and the Heat Index (HI) or the Canadian Humidex. Using
inputs on the side of the instrument, two additional sensor arrays can monitor
up to three locations simultaneously.
Measure airflow, in meters per second, by plugging an optional hot wire
anemometer sensor into a side jack on the unit.
Determine thermal comfort indices, Predicted Mean Vote (PMV) and
Predicted Percent Dissatisfied (PPD), using QuestSuite software.
WET BULB GLOBE TEMPERATURE
The WBGT is a weighted average of the three temperature sensors using the
following formulas:
WBGT (indoor) = 0.7WB + 0.3G
WBGT (outdoor) = 0.7WB + 0.2G + 0.1DB
The resulting WBGT values can then be compared to indices of work-rest
regimens (stay times) based upon work loads.
STAY TIMES
Stay times represent how long a worker should be able to safely work under
heat stress conditions. Select one of three indices for displaying and
printing from the unit: ACGIH Stay Times, NAVY PHEL’s, or EPRI
Action Limits. Refer to Appendix A for more information on the indices.
HEAT INDEX / HUMIDEX
The Heat Index is determined using the dry bulb temperature and relative
humidity. Based upon charts available from the U.S. National Weather
Service, Heat Index represents how an average person feels relative to climate
conditions. For a given temperature, the higher the humidity, the higher the
heat index.