Emerson Process Management rosemount 3300 series manual Surehv, Click the Send Page button 127

Rosemount 3300 Series

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00809-0100-4811, Rev AA October 2002

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SUREHV

The 3300 series has a measurement option which makes it possible to handle interface measurements when the product level is not visible, for example in a full bridle pipe as illustrated in Figure 6-6.In this case the probe is fully immersed into the upper product, and only the interface level is detected by the transmitter. Even if the upper product level drops, it is ignored by the transmitter which continues to measure only the interface level, but the measurement accuracy is reduced since the transmitter does not take into account the influence of the air gap above the product surface.

The Measurement Mode parameter is available via the

HART command [1, 3, 9]. Choose the ,QWHUIDFH￿ZKHQ￿,PPHUVHG￿3UREH￿option.

Measurement mode ,QWHUIDFH￿ZKHQ￿,PPHUVHG￿3UREH can also be activated in the RCT software:

1.Open the Setup window.

2.Select the Tank Config tab.

3.Choose Measurement Mode ,QWHUIDFH￿ZKHQ￿,PPHUVHG￿3UREH.

4.Click the Send Page button.

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Do not use Measurement Mode ,QWHUIDFH￿ZKHQ￿,PPHUVHG￿3UREH￿in “standard” applications when both Interface Level and Product Level are measured.

If the product level drops, the air filled region in the upper part of the pipe will slightly reduce the measurement accuracy of the interface level. To achieve high accuracy in this measuement mode the probe must be fully immersed.

Figure 6-6. Interface Level measurements in a full bridle pipe.

#￿￿￿￿￿￿￿￿￿$￿￿￿￿￿￿￿	#	LEVEL
		INTERFACE
#￿￿￿￿￿￿￿￿￿!￿"￿￿
	￿￿￿￿￿￿!￿"￿￿￿￿ ￿￿￿	BRIDLEINTERFACE/BRIDLE

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Adjust Threshold T2 if the level pulse is not detected.

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