Dwyer TFM-LP - Manual (Page 18)

F-20-TF-L, pg. 18 of 30
ii.) Adjust the scaling endpoints in the display or data acquisition system. For
example:
For a flow range of 50-500ml/min with a 0-5VDC output:
With a constant flow and constant 5VDC output the actual volume
measured over 60 seconds was 405ml.
Therefore the actual flow rate is:
(405 / 60) x 60 = 405ml/min
The display or data acquisition system may now be configured as
follows:
0 VDC = Zero flow
5VDC = 405ml/min
iii.) Apply the error factor to each flow reading taken. For example:
For a flow range of 0.2-2.0l/min connected to a display:
With a constant flow rate of 2.0 l/min on the display, the actual
volume measured over 20 seconds was 0.7l
Therefore the actual flow rate is:
(0.7 / 20) x 60 = 2.1 l/min
The error is therefore 2.1 – 2.0 = 0.1 l/min or 5%
If the display shows an uncorrected flow rate of 1.4 l/min then :
Corrected flow rate = Uncorrected flow rate + error
Corrected flow rate = 1.4 + 5% = 1.47 l/min