Hach 8450, Инструкция по эксплуатации инструмента

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Page 58
Calibrating with a Simulated Input
16116Maintenance.fm
Section 4
• American Sigma Probe Test Fixture, Cat. No. 16084 or equivalent
connector and wired resistors (
Figure 38 ).
To Perform Simulation
1. Set up the equipment as indicated in Figure 38 . Power equipment OFF
while connecting.
2. Set power supply voltage adjustment control to zero volts (off). Power all
equipment on and make certain output voltage reads 0 volts on the
precision voltmeter.
3. Ensure that all instrument's parameter settings have been documented
then restore the factory default settings by applying the magnet to the icon
while re-applying power to the Residual Chlorine Monitor. Continue to
hold the magnet in place until the instrument's sign-on screen appears
(Model #, Software version, etc....). Remove the magnet.
4. Enter the calibration (CAL) menu and select “ZERO” calibration. When
the “zero cal complete” message appears, exit the menu by selecting the
icon.
5. Adjust the voltage input to 600 mV (Span) then enter the calibration
“Span” menu. Select again and use the icons to adjust the displayed
concentration to 10.0 ppm. Select and, after 15 seconds, verify the
relative probe sensitivity value (displayed in lower right corner of display)
is within 150% (±20).
Figure 38 Simulated Input Calibration Setup
Equivalent Probe Test Fixture Wiring
End View
A
B
C
D
E
F
Red
Grn, 100 K , 1%
Ω
Blk, 100 K , 1%
Ω
Side View
mV
+
-
000.00
0 and 600 mV
isolated power
supply Precision
Volt meter
Grn
Blk
Red
(not used)
8450 Meter
Test Fixture
(Cat. No. 16084)