Omega Engineering LVU-90 Calibration, Current to Distance Conversion Chart Nominal, Step Six

CALIBRATION

Step Six

The LVCN-90 is factory calibrated with a fixed measurement span of 6 feet. The 4 mA position is located 72" from the transducer face. The 20 mA position is located 3.6 inches from the transducer face. Refer to the current to distance and distance to current conversion charts in step seven for reading the current output.

1.Connect a multimeter in series to read the current output.

2.Verify that as the distance from the liquid to the LVCN-90 increases, the current signal decreases.

3.Verify that as the distance from the liquid to the LVCN-90 decreases, the current signal increases.

Power		5		Power		20
Supply	4		6	Supply	19		21
			mA				mA
	com		(+)		com		(+)

3.6"

20 mA

72"

4 mA

LED Indication

The LVCN-90 features a single LED indicator which is used for power and fail-safe indication. During normal operation, the LED will be ON continuously to indicate that the transmitter has power and a strong echo signal return strength. Should the LED begin to FLASH, it indicates that the transmitter has no signal return strength and the device has gone into a fail-safe condition. During the fail-safe condition, the current will increase up to 22 mA and hold until the acoustic signal is reacquired. Once reacquired, the LED will turn back ON continuously and the current will indicate the appropriate mea- sured value.

	POWER
	LED
(-)	(+)
GND	12-36 VDC
4-20 mA

CALIBRATION

Step Seven

Current to Distance Conversion Chart (Nominal)

Current	Distance	Current	Distance	Current	Distance
mA	inches	mA	inches	mA	inches
2 0	0 3 . 6	1 4	2 9 . 2	0 8	5 4 . 9
1 9	0 7 . 9	1 3	3 3 . 5	0 7	5 9 . 2
1 8	1 2 . 1	1 2	3 7 . 8	0 6	6 3 . 5
1 7	1 6 . 4	11	4 2 . 1	0 5	6 7 . 7
1 6	2 0 . 7	1 0	4 6 . 3	0 4	7 2 . 0
1 5	2 5 . 0	0 9	5 0 . 6

Distance to Current Conversion Chart (Nominal)

Distance	Current		Distance		Current		Distance	Current
inches	mA			inches		mA	inches	mA
3 . 6	2 0 . 0	3 0			1 3 . 8		6 0	0 6 . 8
0 6	1 9 . 4	3 6			1 2 . 4		6 6	0 5 . 4
1 2	1 8 . 0	4 2			11 . 0		7 2	0 4 . 0
1 8	1 6 . 6	4 8			0 9 . 6
2 4	1 5 . 2	5 4			0 8 . 2

3.6"

20 mA

72"

68.4"

4 mA