Hach 8450, Instrument Manual

Page: 20 / 66

Page 20
4-20 mA Surge Protector
16116Install.fm
Section 2
2.7.2 Test and Check Procedure
2.7.3 4-20 mA Device Connection
This process contains three major steps:
• Hooking the 4-20 mA device in series with a milliampmeter and the 8400
meter.
• Performing the 4 mA and 20 mA adjustments for each device on each
channel.
• Removing the milliampmeter and connecting the 4-20 mA device directly
to the surge protectors on each channel.
Activate Result
F 1. From the Main screen brings up the Main menu.
↑
2. Several times to move to >VMA.
E 3. Selection menu: CH1, CH2, ADJ.
↑
4. Several times to move to >ADJ.
E 5. Channel selection screen: >---NONE---.
E 6. Enter channel selection. [---NONE--- blinks.]
↑
7. “CH 1 4.00 mA” display blinks.
E 8. Enters > CH1 4.00 mA [only (>) blinks].
9. Milliampmeter displays 4 mA ±2% (3.92 to 4.08 mA).
↓
10. Adjust mA Output. To select > Adjust---.
E 11. Enters Adjust.
↑↓
12. Adjust output up or down as need until milliampmeter reads
4 mA ±2% (3.92 to 4.08) mA.
E 13. Enters (accepts the adjustment).
↑
14. Return to channel selection. [Displays: >CH1 4.00 mA...]
E 15. Enter Channel selection.
↑
16. “CH 1 20.0 mA” display blinks.
E 17. Enters >CH1 20.0 mA [only (>) blinks].
18. Milliampmeter displays 20 mA ±2% (19.6 to 2.04 mA).
↓
19. Adjust 20 mA Output: To select >Adjust---.
E 20. Enters Adjust.
↑↓
21. Adjust output up or down as needed until milliampmeter reads
20 mA ±2% (19.6 to 2.04 mA).
E 22. Enters (accepts) the adjustment.
23. Continue On to Check Channel 2 in the same manner. Move
milliampmeter leads to channel 2 extension leads and tape
insulate the bare channel 1 leads to avoid the possibility of
shorting.
↑
24. Moves to the channel line of the menu.
E 25. Channel menu line blinks.
↑
(5 times) 26. Displays CH2 4.00 mA.
E 27. Enters > CH2 4.00 mA [only (>) blinks].
28. Repeat steps 9 through 22 to check 4 mA and 20 mA outputs
of channel 2.