Tecfluid MC-01 - Manual (Page 9)

Cod:E-MI-2151061 I Rev:1
9
6 USEFUL EXAMPLES OF CALCULATIONS
6.1 Measurement error corrections
The calibration of the mechanical flowmeters is accomplished using, for the liquid, water at 20
o
C
thus obtaining a calibration for a liquid of density 1 kg/l and viscosity of 1 mPas. If the flowmeter is used with
a liquid of other characteristics from the above specified o for reasons of turbulences in the flow,
measurement errors can be induced.
To correct these types of errors we can modify the pulses per litre ( Factor I/L) programmed in the
MC-01.
Example 1 - Shortage of volume
If we have a flowmeter which specifies 200 pulses per litre, and when we check the volume of a
batch, we find that instead of having 100 litres as programmed, we only have 95 litres (5% less) and we
must apply the following correction:
Fn = Factor Pulses per litre ( new )
= ? (210,526)
F = Factor pulses per litre ( original ) = 200
V = Expected Volume = 100
Vr = Real Volume = 95
In this case counting 200 pulses per litre for 100 litres (total of 20.000 pulses) we have been given in
fact 95 litres, thus we must increase the value of pulses per litre to 210,526.
Example 2 - Excess of volume
If we have a flowmeter which specifies 200 pulses per litre, and when we check the volume of a
batch, we find that instead of having 100 litres as programmed, we only have 105 litres (5% more) and we
must apply the following correction:
Fn = Factor Pulses per litre ( new )
= ? (190,476)
F = Factor pulses per litre ( original ) = 200
V = Expected Volume = 100
Vr = Real Volume = 105
In this case counting 200 pulses per litre for 100 litres (total of 20.000 pulses) we have been given in
fact 105 litres, thus we must decrease the value of pulses per litre to 190,476.
V
V x F
= F
r
n
V
V x F
= F
r
n