Ma Calibration - Hach 900 MAX Instrument Manual

Section 6
6.3.3 4–20 mA Calibration
Page 88
4–20 mA Option
5. Select an analog Input Channel (e.g., channel 1, 2, 3, or, flow, etc.) to
assign to that output. Press
channel names. When the desired channel is displayed, press
11:00 AM 21 - APR - 01
ACCEPT
INPUT CHANNEL:
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
ACCEPT
4 mA INPUT VALUE
CLEAR
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.
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
CALIBRATION > 4–20 mA OUTPUTS.
2. Connect a multimeter to the 4–20 mA current outputs per
Figure 25.
3. Make sure that the 4–20 mA output is enabled. If it is not enabled, press
so that the display shows Enabled and press
CHANGE CHOICE
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
to cycle through the
CHANGE CHOICE
4–20 mA OUTPUTS
FLOW
4–20 mA OUTPUTS
0.00 mgd
OPTIONS > ADVANCED OPTIONS >
.
ACCEPT
CHANGE
CHOICE
CANCEL
Figure 24 and
.
ACCEPT
.
ACCEPT
8990cm.fm