Calibration – American Magnetics 286 Multi-Sensor Liquid Level Instrument (CE-Marked) User Manual

Page 37

Calibration

Closed dewar calibration

9. Calculate the factor C

adj

using the following equation:

where L

total

is the total sensor length in inches, L

active

is the active

sensor length in inches, and

is the dielectric constant of the target

liquid.

10. Enter C

adj

into the instrument by placing the instrument in the

custom approximate calibration factor entry screen as documented
in paragraph 3.3.4.2 on page 31.

It will be necessary to

ESC

to the sensor input selection screen and

choose the

Select

option in order to traverse the calibration menu

tree and arrive at the custom approximate calibration factor entry
screen. Ensure that the same calibration used to this point of the
presetting procedure is selected for the entry of a custom
approximate calibration factor.

The presetting procedure is complete. The presetting procedure has
temporarily calibrated a measurement span that should prevent the fill for
a MAX calibration from exceeding a 100% indication from the Model 286.
Proceed to the remainder of the closed dewar calibration procedure as
presented below.

3.2.2.2 Completing the closed dewar calibration procedure

1. Install the sensor in the dewar and energize the instrument with

the sensor appropriately connected to the instrument (see the
system diagram on page 5).

2. Again, re-enter the calibration menu by using the passcode if

necessary, and select the identical sensor input to calibrate as
selected in the presetting procedure.

3. Choose the

Perform

option and select the identical calibration as

selected for the presetting procedure.

4. Verify the active length value previously entered in the presetting

procedure.

5. Place the instrument in the MIN/MAX entry screen as documented

in paragraph 3.3.5.3 on page 34.

6. Connect a strip chart recorder to the 0-10 V recorder output

terminals available on the rear panel of the instrument if an analog
output option was purchased. If the recorder output is not

adj

120 1

–

(

)

active

total

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