ETS-Lindgren HI-1501, User Manual

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HI n 1501 Manual Page — 5
Accuracy
The accuracy of this instrument is within ± 1 db
(+25%, -20%) when used according to these
instructions:
1. Always use a clean Holaday spacer cone.
Accuracy will be affected by wear of the cone and
by dirt and metallic particles which may become
imbedded in the EPS (expanded polystyrene -
Styrofoam).
2. If the instrument is to be used continuously for an
extended period of time, the condition of the
batteries must be checked by rotating the selector
switch to the BATT TEST position at least once
every 15 minutes.
3. The normal operating temperature range is
between 60
/
and 90
/
F. If used outside this
range, an additional error will be introduced. This
error can be approximated as -0.14% per
Fahrenheit degree. The negative temperature
coefficient means that the instrument reads high
at lower temperatures and low at higher
temperatures.
4. The parameters which affect the accuracy of this
instrument are listed along with the error
contribution of each in the following table.