General Tools and Instruments HT20 - Manual (Page 13)

memory, potentially limiting its capacity to capture important
events such as an unexpected excursion of temperature or
humidity. Conversely, using the longest sampling time setting
of 12 hours will likely cause important events to go
undetected.
If you are an experienced data logger, you already know how
to choose the optimum sampling time for your application. If
you are a novice, pick a sampling time closer to the minimum
sampling time than the maximum, on the assumption that the
HT20 probably has enough memory (8000 pairs of humidity
and temperature readings) to store all the data you ask the
meter to log—unless you use it to log data for months, rather
than weeks or days.
If you wish, you can also drag the sliders shown in the figure to
set high and low alarm setpoints for temperature and humidity.
Once you have chosen your data logging parameters, click
Setup. A window will appear advising that “The device is set
up successfully.” Clicking Setup also synchronizes the HT20’s
internal clock with your computer’s clock, giving all data logs
to be captured an absolute time reference.
You can now unplug the HT20 from your computer’s USB port.
The unit is in “standby” mode, ready to begin logging data.
OPERATING INSTRUCTIONS
DEPLOY THE UNIT
The HT20 is particularly easy to deploy on a job site because
the unit does not need to be plugged into a computer to be
activated (ready to start logging data). Working together, the
MODE button and the LCD serve as the control and indicators
needed to: 1) start and stop data logging and 2) verify and
change the unit’s working status.
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HT20 - Manual–FINAL_REV_0316121_awb 3/16/12 4:02 PM Page 13