ULTRAFLOW® 54 DN15-125
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Kamstrup A/S · Technical description · 5512-2464_D1_GB_09.2021
8.4
Optimization in connection with calibration
To make a rational test of ULTRAFLOW®, it must be possible to reproduce the test results. This is also very important if
the tested sensors are to be adjusted.
Experience shows that ULTRAFLOW® operates with standard deviations of 0.3…0.4 % at q
i
and 0.2…0.3 % a
t q
p
. This is
standard deviations at 300…500 pulses at q
i
, 3000…5000 at q
p
, and flying start/stop.
In connection with the optimization of calibration, the following subcomponents can be considered:
Pressure:
Optimal working pressure is 4…6 bar of static pressure. This minimises the risk of air and cavitation.
Temperature: Calibration temperature according to EN 1434-5 is 50 °C ± 5 °C for heat meters and 15 °C ± 5 °C for cooling
meters.
<
For further information regarding allowable test conditions such as water temperature and flow of the individual
ULTRAFLOW®, see the approval of ULTRAFLOW® (see paragraph
Water quality: Recommended water quality as described in CEN TR 16911 and AGFW FW510
Installation (mechanical conditions):
To avoid flow disturbances, the inlet pipes and distance pieces must have the same nominal diameter as the sensors (see
). There should be min. 5 x DN between the sensors. In connection with bends, etc., there should be a minimum
distance of 10 x DN. If tests are made at low flow with a bypass at right angles to the pipe, it will be an advantage to
mount an absorber of pressure fluctuations caused by the perpendicular inlet. This can be a flexible tube on the bypass.
In addition, it will be an advantage to mount a flow straightener before the first distance piece. Flow disturbances such
as pulsations, e.g. pump fluctuations must be minimised. In connection with calibration, a code of practice for distance
pieces has been made on the basis of many years' experience:
The lengths of the distance pieces must be 10 x DN.
The diameter of the distance pieces must be:
Connection
Distance piece
G¾B (R½) DN15
ø15
G1B (R¾) DN20
ø20
DN20
ø20
G5/4B (R1) DN25
ø25
DN25
ø25
G1½B (R5/4) DN32
ø32
DN32
ø32
G2B (R1½) DN40
ø40
DN40
ø40
DN50
ø50
DN65
ø65
DN80
ø80
DN100
ø100
DN125
ø125
Table 32. Distance pieces.
At horizontal mounting of ULTRAFLOW® 54, which is typical for a flow bench, pay special attention to
. Note that ULTRAFLOW® must NOT be evacuated (exposed to vacuum).
Installation (electrical conditions):
To avoid interference from the outside as well as to obtain an electrical interface to MULTICAL®, it is recommended to
use a Pulse Tester (see paragraph
) or to connect a Pulse Transmitter (see paragraph
) between ULTRAFLOW® and
the relevant test equipment that counts pulses to achieve galvanic separation. If the test equipment supports NOWA, see
paragraph