Table of Contents
Advertisement
▷ In the test procedure described below, it is guar-
anteed that the unit under test always performs
full measuring unit rotations.
Master meter test procedure
Q
N
1
2
3
Set the test flow rate.
Start measuring the reference time Δt
er 1.
Immediately afterwards, briefly press the selec-
tion key
on the index to start the cyclic test
on the unit under test – marker 2. The index will
thus be "armed" for measurement.
▷ As soon as one of the significant sensor posi-
tions has been detected, the unit changes to
measuring mode – marker 3. A beep confirms
the start of the measurement.
▷ Once the required minimum testing time has
been reached, the measurement can be termi-
nated – marker 4.
4 Briefly press the selection key
the measurement.
▷ Measurement on the unit under test stops au-
tomatically once the full number of measuring
unit revolutions has been completed – marker 5.
▷ A beep acknowledges the end of the measure-
ment.
▷ Measurement is terminated automatically after
5 hours.
5 Stop the test on the master meter – marker 6.
▷ The measurements are then available.
6 Read off the flow rate on the master meter or
calculate if necessary:
a) taking into account the inherent error of the
master meter:
Q
= V
x 3600 s/h / ((1+F
act,N
N
b) If the inherent error of the master meter has
already been taken into account in the dis-
played volume (V
Q
= V
x 3600 s/h / Δt
act,N
act,N
7 Calculate the flow rate on the unit under test:
Q
= V
/Δt
P
P
P
8 The accuracy is checked by comparing the flow
rates. The pressure and temperature values of
the unit under test corrected with reference to
t
N
t
P
4
5
at mark-
N
in order to end
/100) x Δt
N
= V
):
N
act,N
N
the master meter have already been taken into
account here:
F
= 100% x (((Q
P
T
)) - 1)
P
The following applies:
T
= (273.15 + {t
P
p
= {p
} mbar
P
g
If Q
in step 7 is determined from the non-con-
P
verted volume V
T
= (273.15 + {t
P
where t
= relevant gas temperature on the unit
g
6
under test in °C (display)
▷ The curly brackets mean "numerical value of".
▷ On a nozzle test rig with a known flow rate,
steps and 6 can be omitted.
▷ The error calculation is based on PTB Testing
Instructions, Volume 29: "Messgeräte für Gas –
Gaszähler" (Measuring instruments for gas – gas
meters), Edition 2003.
Cyclic test with a given volume
Test load and minimum test volumes for the test with
index readout:
Q
max
Type
in
m
3
/h
BK-G6
10
BK-G10
16
BK-G16
25
BK-G25
40
BK-G40
65
Master meter test procedure
V
N
8
7
9
To activate the cyclic test on the unit under test,
briefly press the selection key
marker 7. The index will thus be "armed" for
measurement.
)
Start the test on the master meter – marker 8.
N
▷ As soon as one of the significant sensor posi-
tions has been detected, the unit changes to
measuring mode – marker 9.
Test is ended – marker 10.
4 Read off the test results on the unit under test.
▷ The measured values are updated with each 1/8
revolution of the measuring unit.
GB-11
x p
x T
) / (Q
P
P
N
act,N
}) K
g
, the following applies:
P
}) K
g
Cyclic
Test volume in dm
volume
Q
0.2 Q
min
max
in dm
3
6
180
360
6
180
360
6
180
360
12
360
720
18
540
1080
on the index –
x p
x
N
3
at
Q
max
360
360
360
720
1080
10
11
Advertisement
Table of Contents
