Turbines, Inc. CDS1000 - Field Calibration; Calibration Methods and Kfactor Calculation

Turbines Incorporated Cryogenic Flow Delivery System CDS1000 Manual (Rev E)
CDS1000 Page 19
Field Calibration
Adjustment of a Kfactor that shifted over time or due to influences of the installation can be
accomplished in the field under controlled conditions. Field calibration of the Kfactor by weigh
scale isn’t recommended when the CDS1000 is programmed to use linearization.
Calibration Methods:
The two most popular field calibration methods are a calibration prover or a weigh scale. The
metrological preferred method is the prover due to superior accuracy. The scale offers an
approximation and should be conducted with large volumes to minimize the error introduced
by the magnitude of the scale resolution (intervals). The best practice when using a scale is to
place the receiving vessel on the scale. For any procedure the CDS1000 should be in the
Prove mode. Depress the Setup key, enter the password when prompted, depress Enter and
then ESC; this places the CDS1000 in the prove mode operating screen. The Prove mode
allows repeated access to adjust the Kfactor while the cooldown timer, flow inhibit of the
reset function and Kfactor are disabled.
Calculating new Kfactors:
Calculating a new Kfactor is the identical regardless of calibration method. Although the
TPS1500 Flow Calibration Prover calculates the new Kfactor not all competitive systems
offer this convenience. A simple formula calculates the new Kfactor.
Note: Confirm that the engineering units of both the calibration method and the
CDS1000 are the same by using the appropriate liquid equivalencies.
TotalnCalibratio
KfactorpresenttotalCDS
KfactorNew
*1000

Example: Calibration total = 50,000 lbs., CDS1000 total = 49,000 lbs., present Kfactor = 150
147
000,50
150*000,49
*1000

TotalnCalibratio
KfactorpresenttotalCDS
KfactorNew
Example: Calibration total = 50,000 lbs. LIN, CDS1000 total = 7265 gals,
present Kfactor = 150
Convert 50,000 lbs. LIN to gallons:
gal
gal
7413
/#745.6
000,50

147
7413
150*7265
*1000

TotalnCalibratio
KfactorpresenttotalCDS
KfactorNew