Ronan X96S MASS FLOW GAUGE Manuel d'utilisateur télécharger pdf (Page 51)

Calibration

Initial calibration consists of two parts, the flow-rate calibration and the density calibration.

Calibration correlates the X96S's output to your actual process density. It instructs the microprocessor to

read and store the detector counts for a low and high density of process. Once the system is conditioned to

recognize the low and high density, it will provide a 4-20 mA output over the entire range of interest.

Temperature Compensation

If temperature compensation is required for your measurement accuracy, you will want to enable that

feature before doing the calibration.

WHY is Temperature Compensation Used?

Process temperature variation will cause a change in process density. If the change in density due to

temperature variation is significant, the measurement could be influenced. In those cases, temperature

compensation is used to offset the influence.

WHEN is Temperature Compensation Needed?

In general, WIDE temperature variations over NARROW measurement spans usually require temperature

compensation.

For example, a 25ºC change in process temperature over a measurement span of 0.6 SpG would NOT

require temperature compensation. However, a 25ºC change in process temperature over a measurement

span of 0.1 SpG would require temperature compensation.

As a rule-of-thumb, follow this guideline:

If your change in process temperature (in ºC) is greater than 50 times your density span, you will

need to use temperature compensation.

EXAMPLE (If using SA1):

IF: /\ T = 25º C

AND: Density Span = 0.6

THEN: 50 * 0.6= 30 > 25

THEREFORE:

Temp comp IS NOT needed.

HOWEVER:

IF: /\ T = 25º C

AND: Density Span = 0.1

THEN: 50 * 0.1= 5 < 25

THEREFORE:

Temp comp IS needed

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Ronan X96S MASS FLOW GAUGE Manuel d'utilisateur Page 51