General Tools and Instruments CIH20DL - Manual (Page 17)

On the dashboard, the default units are °F for temperature and m/s for air speed. To change
the air speed unit, left-click the red box containing m/s and select one of the four other units
as the default. To switch to °F as the IR and air temperature unit, click on °F in the red box.
These defaults must be reset each time you the open the program.
Using the Meter to Log Data
Before logging data,
close the Anemometer AP program and disconnect the CIH20DL
from your computer in that order (see Warning on p. 16). You should then use the
Advanced Settings Menu (see p. 12 and following) to set the current time and date in the
meter. Doing so will give the data you log an absolute temporal reference point, making it
more credible and valuable. The Advanced Settings Menu also allows you to use air speed
and temperature units other than the default m/s and °F, respectively.
Finally—and most important—the Advanced Settings Menu enables you to determine the
optimum value of sampling time for the purposes of your application. Using the shortest
setting of 5 seconds may result in too much essentially identical data being stored in
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
59 minutes, 59 seconds 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 than the maximum sampling time, on the assumption that the meter probably has
enough memory (20,000 sets of 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.
Because most data logging is done over a long period of time, General recommends that you
change the meter’s power supply from its 9V battery to an external source of AC power
before beginning a logging session. Running on AC power enables the meter to log data
indefinitely, not just until the battery discharges.
To switch to AC power, attach the correct type of plug for your locale (American-style
blades or European-style round prongs) to the socket of the supplied power cable. The top of
each plug has square corners. Push the lip on the plug’s top edge at an angle into the slot in
the top of the socket’s cavity (marked by an arrow). Then push the bottom of the plug down
and into the cavity until the spring-loaded latch secures it. Finally, insert the mini B-type plug
end of the power cable into the USB jack on the side of the meter (Fig. 1, Callout 7) and plug
the other end into an AC outlet.
To begin logging data, extend and secure the probe as the application dictates and then
press and hold the REC button for at least 3 seconds. This will cause the phrase DATA LOG
to appear on the bottom of the meter’s LCD.
To stop logging data, press and hold the REC button again. This will cause the DATA LOG
indication to disappear. Once the meter exits Data Logging mode, it will automatically power
off in 30 minutes (assuming you plugged it into an AC outlet for the logging session, as
recommended earlier). Finally, disconnect the cable applying AC power from both the meter
and the AC outlet. Using the instructions above as a guide, reconfigure the power cable as a
USB cable by detaching the power plug from the socket at the cable’s mini-A plug end.
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CIH20DL-FINAL-122111_awb 12/21/11 9:58 AM Page 17