1. INTRODUCTION
Page 11
© 1995 - 2010 Fluke Corporation, DH Instruments Division
1.2.5.2.3
molbloc-S Pressure Dependent Calibration Types
Note
See your molbloc’s Calibration Report to determine the
calibration type of the molbloc you are using.
Measurement uncertainty (accuracy) specifications for molblocs are valid only for
gases with which the molbloc has been calibrated. All molbloc-S elements are
calibrated in one standard gas, either air or N2, and may be calibrated in other
gases. Calibrations with other gases are optional. The list of gases which can
be measured by molbloc-S is the same as molbloc-L.
DHI
calibration capability
is not maintained at all times for all gases on all molbloc designations. Check for
availability before ordering calibrations.
molbloc-S calibrations are performed over flow ranges corresponding to one of
three pressure ranges, summarized in Table 15.
Table 4:
molbloc-S Calibration Types
CALIBRATION TYPE
(CALIBRATION NAME)
OPERATING PRESSURE
Low pressure
(LP)
20 to 200 kPa absolute
(3 to 30 psia)
upstream
of molbloc
Standard pressure
(SP)
50 to 500 kPa absolute
(7 to 70 psia)
upstream
of molbloc
High pressure
(HP)
200 to 2000 kPa absolute
(29 to 290 psia)
upstream
of molbloc
Note
molbloc-S flow measurements are valid only when the ratio of
pressure downstream to the pressure upstream of the nozzle is
low enough to assure a critical (choked) flow (see Section 3.1.5).
