Siemens SITRANS FUS1010 NEMA-4X/ IP 65 manual Calibrate Flow Rate, Kc Calibration, To calculate Kc

Section 2 1010NFM-3J

2.7.3 CALIBRATE FLOW RATE

The 1010’s intrinsic calibration is excellent as confirmed by numerous laboratory and field trials under diverse application conditions. We thus can confidently say that in any given application, the majority of conventional flowmeters can not match the system’s measurement range or its linearity. Some appli- cations may require an output adjustment to match an official external reference. The Calibrate Flow Rate menu allows you to select a calibration mode. The right-hand column shows the active calibration mode. You can select Intrinsic (factory), Kc (Slope Correction) or Multipoint (Non-linear) Calibration. Selecting either of the external calibration modes will not eliminate the Intrinsic (factory) calibration. You can use this menu cell to switch between Intrinsic, Kc or Multipoint at any time.

Kc Calibration

For most applications, the measured flow range produces a linear meter response. Therefore, the Kc (slope correction) calibration is the preferred method since it only requires a single correction factor for all the flow rates encountered. Changing the calibration can cause profound changes in a flowmeter’s operating characteristics. Use only the most respected flow standard to obtain a correction factor. The percentage you enter must provide an accurate and consistent shift across the entire flow range anticipated for the application.

To obtain the Kc factor, compare flow total data taken simultaneously from the 1010 and a reference meter whose accuracy meets the required standard. Allow both meters to accumulate flow total data long enough to average out any differences due to flow fluctuation between the two meter locations. Compare outputs of the two totalizers to determine percentage increase (+) or decrease (-) that is necessary to produce the best average correlation between System 1010 and the reference standard. For example, entering [-0.29] will produce a reduction of 0.29% in the calibration at all flow rates. NOTE: Always enter the + or - sign first.

To calculate Kc:	Kc =	Actual Rate
	Kc =
		Indicated Rate -1

To enter the Kc Factor:

To enable numeric entry press .

x100100

Use the numeric keys to enter the required Kc (as calculated above). Note that the Kc value can be negative or positive. Enter the - or + sign first, then type in the calibrated value.

To store the data press ENT .

Note that Kc now appears in the right-hand column of the [Calibrate Flow Rate] menu cell with its new value. Also note that this Kc value can be viewed on the site printout.

MultiPoint Calibration

MultiPoint calibration serves applications that require a non-linear meter calibration. You can enter correction factors for up to ten significant points over the entire measurement range. This is accom- plished by:

(a)Selecting up to 10 separate calibration points by entering a raw (un-calibrated) flow rate.

(b)Entering a negative or positive correction for each calibration point that you select.

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