Kamstrup MULTICAL 402, Technical Description, Page: 91 / 113

MULTICAL® 402
Kamstrup A/S · Technical Description · 5512-742_M1_GB_01.2016
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13.3 Handling of different test methods
13.3.1 Standing start/stop
Standing start/stop is a method used for testing the flow meter’s accuracy. The test must be carried out while the
meter is mounted in a flow test stand. The flow through the meter is cut off. Now the verification registers are
reset and the flow is opened for a period of time while the water running through the meter is being collected.
Having switched off the flow again the volume of the collected water is compared to the volume counted by the
meter. Generally standing start/stop requires bigger test volume than flying start/stop.
13.3.1.1
Condition: MULTICAL
Standing start/stop at display reading of V' and Q'
®
V' and Q' are reset by double key pressure – i.e. both keys are pressed continuously for 5-6 seconds. Thus, both
registers are reset.
402 must be in verification mode.
The selected display reading is updated at intervals of 4 sec.
13.3.1.2
Condition: MULTICAL
Standing start/stop using pulse outputs
®
Verification pulses are connected as described in paragraph 13.2.4 above.
402 must be in verification mode.
13.3.2 Flying start/stop
“Flying start/stop” is the most frequently used method for testing the flow meter’s accuracy. The test must be
carried out while the meter is mounted in a flow test stand and the water flow through the meter is constant.
The meter’s counting of volume and energy in the high-resolution verification registers can be controlled by the
PULSE-INOUT1 (pin 8) connection of the verification plug. The meter only counts as long as PULSE-INOUT1 is
connected. Based on the time, during which PULSE-INOUT1 is connected, and the fact that the flow through the
meter/flow stand is constant, the theoretical volume through the meter can be calculated and compared to the
volume counted by the meter.
As the meter counts volume and energy every 4 seconds (in verification mode – see paragraph 13.2.4), and as
counts around start and stop flanks must be weighted in relation to the time between flank and calculation, it can
take up to four seconds from PULSE-INOUT1 has been disconnected until the result can be read. Furthermore, the
time between two flanks must not be less than 4 seconds.
At the very moment PULSE-INOUT1 is connected the verification registers are reset. Maximum 4 seconds after this
the verification registers are counted the first time followed by normal counting in the registers every 4 seconds.