Honeywell SMV 3000 About Square Root Output Square Root Dropout, Flow 0utput Full MA dc Scale

6.6 DPConf Configuration - PV1, Continued

About Square Root Output, continued

Square Root Dropout

Example: If you have an application with a differential pressure range of 0 to 100 inches of water with an input of 49 inches of water, substituting into the above formulas yields:

49

100 • 100 = 49%

49%

100 • 100 = 70% Flow, and

70% • 16 + 4 = 15.2 mA dc Output

To avoid unstable output at PV1 readings near zero, the SMV 3000 transmitter automatically drops square root conformity and changes to linear conformity for low differential pressure readings. As shown in Figure 21, the square root dropout point is between 0.4 and 0.5 % of differential pressure input.

Figure 21 Square Root Dropout Points for PV1

	Flow
0utput	(% Full
(mA dc)	Scale)
6.4	15
	14
	13
	12
	11		Dropout Points
5.6	10					e
					v
					r
					u
					C
					t
	9				o
					o
				R
				e
				r
				a
				u
	8			q
				S
	7
	6
4.8	5
	4
	3
	2
	1
4	0
	0	0.2	0.4	0.6	0.8		1	1.2	1.4
			Differential Pressure (% Full Scale)						22508

Continued on next page

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