Hach 1950Plus, Инструкция по эксплуатации инструмента, Страница: 133 / 188

Section 8
Page 133
UVTOCTroubleshooting and Service.fm
Maintenance Code Diagnostics
M03
Span Stability
Four attempts at a span calibration are made before this error is reported.
There are several reasons why this can occur.
The standard solution is varying in purity, is not of
constant supply, or has not been introduced for
sufficiently long time.
Ensure a constant flow of standard. Verify the calibration
valves are fully open. Increase the Pre span delay to
ensure that the analyzer has achieved a stable IR CO
2
reading before performing a span.
The persulfate has carbon impurities or it is not being
delivered constantly.
Check the condition of the persulfate delivery system.
TIC extraction/acid mix is not constant. This can be
because no TIC extraction or purely irregular supply of
acid. If there isn't any TIC in the standard, the acid is a
small diluent to the sample actually getting into the
reactor.
Verify acid delivery system constant and that there aren't
any impurities in the acid. Use fresh TIC free calibration
standard.
Leaking fluid or gas system. Fix leak.
Poor IR cell heater control.
Verify cell temperature is constant 49 °C ±1 °C.
Increase span size.
M04
Span level
In order to pass an autocalibration, it is necessary to
achieve 65% of the theoretical CO
2
for the applied
standard. For example, if the analyzer is calibrated with
10000 ppm CO
2
and the analyzer is a 1000 mg/L
analyzer, and if the single point standard is 1000 mg/L,
it is expected that the gas produced will be at least
6500 ppm CO
2
.
Expected CO
2
=
=
= 6,500 ppm CO
2
(See above)
Most likely problems:
1. Insufficient oxidation, due to either insufficient
persulfate (supply or strength) or weak or dead UV
lamps. 2. Check the condition of the persulfate delivery
system. Check concentration of persulfate.
Investigate a dead lamp.
3. Bad standard. 4. Remix a standard verifying that it matches the value
entered in the Single cal std menu.
5. Fluid leak. 6. Fix leak.
M05
Maintenance %
The current calibration deviates from the primary
calibration by greater than the Maint % v Pri entry in the
Setup/Tolerance/Maint % screen. See
section 5.2.8.3 on
page 84 .
Increase the Maintenance % in the
Setup\Tolerance\Maintenance % Screen.
Replace peristaltic pump tubing and perform a primary
calibration.
Code
Fault message
Diagnosis Corrective action
0.65 FSD gas
•
CAL STD
•
Analyzer FSD
-----------------------------------------------------------------------
0.65 10,000 1,000
• •
1,000
--------------------------------------------------------