Hach 900 MAX manual 6.3.3 4–20mA Calibration, Section

Section 6

5.Select an analog Input Channel (e.g., channel 1, 2, 3, or, flow, etc.) to assign to that output. Press CHANGE CHOICE to cycle through the channel names. When the desired channel is displayed, press ACCEPT.

11:00 AM 21 - APR - 01		4–20 mA OUTPUTS
			CHANGE
ACCEPT			CHOICE
	INPUT CHANNEL:
	FLOW
CANCEL
	SELECT APPROPRIATE UNITS

6.Assign a channel value to the 4 mA current value. This value is typically 0, however any value can be set. Enter the value of the input needed to generate 4 mA of current at the output.

11:00 AM 21 - APR - 01		4–20 mA OUTPUTS
ACCEPT
	4 mA INPUT VALUE
CLEAR	0.00 mgd		CANCEL
ENTRY
	SELECT APPROPRIATE UNITS

7.Assign an input value to the 20 mA current level.

8.Repeat this process to configure the other 4–20 mA output.

6.3.3 4–20 mA Calibration

After wiring the 4–20 mA connection perform a 4–20 mA output calibration. The 4–20 mA output calibration requires a digital multimeter or access to the 4–20 mA current loop wiring. Two 4–20 mA outputs are available and are designated Output A and Output B. Both outputs are calibrated the same way and are isolated from each other.

Calibration may be performed while the 4–20 mA device is in the current loop, as shown in Figure 24 or disconnected from the current loop as shown in Figure 25. In either case, the multimeter must be set to a 20 milliamp dc range or greater.

1.From the Main Menu, select OPTIONS > ADVANCED OPTIONS >

CALIBRATION > 4–20 mA OUTPUTS.

2.Connect a multimeter to the 4–20 mA current outputs per Figure 24 and Figure 25.

3.Make sure that the 4–20 mA output is enabled. If it is not enabled, press CHANGE CHOICE so that the display shows Enabled and press ACCEPT.

4.Select the output (A or B) to calibrate.

5.Press any key to set the selected output to 4.00 mA dc.

6.Measure the current on the selected output using the multimeter and enter the measured value using the numeric keypad. Press ACCEPT.

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4–20 mA Option	8990cm.fm