Emerson Process Management 1500 manual 2Effect of flow direction on mA outputs 4mA value

Optional Transmitter Configuration

Figure 6-2Effect of flow direction on mA outputs: 4mA value < 0

mA output

20

12

4
	–x	0		x
Reverse					Forward
flow(1)		Zero	flow		flow(2)

Flow direction parameter:

• Forward

outputmA	20			outputmA	20
	12				12
	4				4
	–x	0	x		–x	0	x
	Reverse		Forward		Reverse		Forward
	flow(1)	Zero flow	flow(2)		flow(1)		flow(2)
					Zero flow
Flow direction parameter:				Flow direction parameter:
•	Reverse			•	Absolute value
•	Negate Forward			•	Bidirectional
				•	Negate Bidirectional

Using the Transmitter

Optional

mA output configuration:		(1)	Process fluid flowing in opposite direction from flow direction arrow on sensor.
• 20 mA value = x		(2)	Process fluid flowing in same direction as flow direction arrow on sensor.
•	4 mA value = –x
•	–x < 0

To set the 4 mA and 20 mA values, see Section 4.5.2.

Configuration

Example 1	Configuration:
	•	Flow direction = Forward
	•	mA output: 4 mA = 0 g/s; 20 mA = 100 g/s
	(See the first graph in Figure 6-1.)

As a result:

•Under conditions of reverse flow or zero flow, the mA output level is 4 mA.

•Under conditions of forward flow, up to a flow rate of 100 g/s, the mA output level varies between 4 mA and 20 mA in proportion to (the absolute value of) the flow rate.

•Under conditions of forward flow, if (the absolute value of) the flow rate equals or exceeds 100 g/s, the mA output will be proportional to the flow rate up to 20.5 mA, and will be level at 20.5 mA at higher flow rates.

Filler Configuration

Using the Filler

Configuration and Use Manual 43