KPDM-1
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4.1.4 When pushing and holding "I" button the measurements are performed in series with
an interval 1.5 seconds, when releasing the button the digital information corresponding to the av-
erage value of air (gas) differential pressure for the time of holding the button appears on a display
and will be kept there until the next pushing of "I" button or until switching-off the device.
Attention! Peculiarity of the selected scheme of differential pressure meas-
urement is that the dynamic pressure is indicated on the device display with
an opposite sign. The static pressure is indicated with a real sign, i.e. exces-
sive pressure with a plus sign, and a discharge with a minus sign.
4.1.5 When pushing and holding "P" button there is a sign HV appeared in the upper right
corner of a display, with this the differential pressure values p (mm w.g.) indicated on a display are
converted to the speed values v (m/s) in accordance with the ratio:
___
V= 4.04
√
kr , where
k--- pneumometric tube coefficient recorded in the device memory.
After releasing "P" button the indication of the differential pressure values is restored.
Note:
This operation is valid for calculation of gas flow speed in the magnitude of dynamic pres-
sure only if the indicated values of p are the result of the dynamic pressure measurement and only
for gases, the density of which is close to the density of air under normal conditions.
Speed of gases, the density of which is substantially different from the air density, can be
determined according to the results of measurements with the account of correlations of section 4
of GOST 17.2.4.06-90 by the formula:
_____
Vreal = Vind
√
n /
ρ
, where
Vreal - real speed value,
Vind - speed value indicated on the device display,
n - air density under normal conditions,
ρ
- real gas density.
Summary of Contents for KPDM-1
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