Heath Consultants Detecto-Pak 4 (DP) - Manual (Page 30)

100786-0 Rev. D 05/09
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CHAPTER SIX
VI. CALIBRATION:
The Heath Detecto-Pak 4 is factory calibrated. It is recommended that the
Detecto-Pak 4 be calibrated once a week. However, it is recognized that
the Detecto-Pak 4 will be used for a wide range of applications and for
varying lengths of time. Such variables may cause the operator to develop
his or her own calibration schedule. The operator may see a need for a
more or less frequent calibration schedule.
The Detecto-Pak 4 should also be calibrated after any repair or replacement
of any parts and at any time the operator suspects the instrument’s
calibration has changed.
In addition to calibrating the instrument on a regular basis, the instrument
should be run through a diagnostic check before each use. The check
should include an observation of the external sampling system. Also, a
daily operational check, with a known sample of gas is recommended to
insure the instrument is operating.
A. CALIBRATION GAS
The type of calibration gas and the concentration level of the
calibration gas will be dictated by the particular detection needs
requirements.
The most reliable detection results will be obtained when the Detecto-
Pak 4 is calibrated with a calibration gas containing the same gas
component anticipated in the test area.
Additionally, the concentration of the calibration gas should represent
the level nearest the critical area of detection required. That is, if
an anticipated detection level of a particular gas is 100 ppm, then
a calibration gas of that species at a 100 ppm + 10% concentration
level would be the best calibration gas to use.
Methane has been accepted in the industry as a general calibration
standard for flame ionization detectors such as the Detecto-Pak 4. It
is recommended the Detecto-Pak 4 be calibrated with 100 ppm of
methane + 10% in air for general detecting applications.
**NOTE**
The calibration of the Detecto-Pak 4 with a particular gas species will
provide reliable ppm readings for a target gas of the same species. Meter
readings observed from the testing of a target gas containing a gas
different from the calibration gas species may not represent the actual ppm
concentration in the sampled target gas.