Omega Engineering CN9400 用户手册

2.5

Therefore adjust  

to (-) 18 to correct error.

Notes: (1) 

After making the adjustment the reading will 

immediately change. Allow time for the temperature 

to stabilise at T

2

before making any further adjustment.

At this point, a 

adjustment may be needed, refer

to step 1 above.

(2)  Check that the temperature correctly stabilises at T

2

and then adjust setpoints to T

1

. If an error is present 

at T

1

repeat from step 2.

In addition to the ten temperature inputs, the controller has five

linear input ranges which can be calibrated to display a range of

engineering units. This procedure involves making adjustments to

the controller’s 

, 

and 

adjustments found in

function menu levels 2 and 3.

The controllers linear inputs are in mV. If your transducer 

provides an output in mA this should be converted to mV 

by feeding the controller input via a high stability one ohm 

resistor, see figure page 26. Other low Vdc signals can be 

connected via a suitable voltage divider network to match 

the controller input requirements.

To make a correction when there are different errors across the scale.

2

Adjust using the                  function

2.1

Chose a temperature near the bottom and

another near the top of the scale.

2.2  Run the process at the lower temperature (T

).

Note the error (E

) between the controller and the

instrument readings.

2.3

Repeat at the upper temperature (T

) and note

error (E

).

2.4

Substitute the values for T

1

, T

2

, E

1

and E

2

in the

expression below to calculate

For 

settings see level 2.

Example:     

T

1

T

2

Instrument reading

58°

385°

Controller reading

60°

400°

Error     

(-) 2°

(-) 15°

(-15) - (-2) x 450 = (-13) x 450 = (-)17.9

385 - 58                    327

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