Nippon WA-5A User manual

1
WA-5A
Service Manual
Document No.
NIC-704-2013-01
Date of Issue Mar. 9, 2015
Management Dept. Technical Center Page 1/
WA-5A
Service Manual
Nippon Instruments Corporation
Technical Center
Date Written By Checked By Approved By
1st edition Mar. 9, 2015 Inoue Daito Noda

2
WA-5A
Service Manual
Document No.
NIC-704-2013-01
Date of Issue Mar. 9, 2015
Management Dept. Technical Center Page 2/
Revision History
Ver. Revision Date Reason for Revision Written By Approved By
01 Mar. 9, 2015 First edition issued Inoue Noda
Distribution List
Distributed To
Distribution
Date Distributed To
Distribution
Date Distributed To
Distribution
Date
President -
Executive
Director -
Applied
Technology
Division -
Sales Division -
Development
Division -

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Atmospheric Mercury Analyzer
Mercury WA-5A Service Manual
Table of contents
1. OUTLINE..........................................................................................................................5
1.1 Outline.........................................................................................................................5
1.2 Basic configuration of this instrument..........................................................................5
1.3 Component description of mercury analyzer...............................................................6
1.3.1 Front (inside of front cover)...................................................................................6
1.3.2 Rear......................................................................................................................7
1.3.3 Inside of top cover ................................................................................................8
1.3.4 Inside of right side cover.......................................................................................9
1.3.5 Inside of left side cover.......................................................................................10
1.4 Readers for whom this service manual is intended...................................................10
2. SAFETY..........................................................................................................................11
2.1 Meanings and explanations of symbols.....................................................................11
2.2 Cautions concerning installation................................................................................11
2.3 Cautions concerning maintenance............................................................................11
3. MAINTENANCE..............................................................................................................12
3.1 Inspection items........................................................................................................12
3.1.1 Daily inspection ..................................................................................................12
3.1.2 Yearly inspection.................................................................................................13
3.2 Errors and warnings..................................................................................................14
3.3 Troubleshooting.........................................................................................................17
3.3.1 Fall of sensitivity .................................................................................................17
3.3.2 Abnormal blank value .........................................................................................18
3.3.3 Abnormal rise in sensitivity .................................................................................18
3.4 Maintenance..............................................................................................................19
3.4.1 Checking of leak.................................................................................................19
3.4.2 Replacement of septum......................................................................................20
3.4.3 Cleaning of gas washing bottle and dehumidifying bottle...................................20
3.4.4 Removal and fixing of cover ...............................................................................21
3.4.5 Removal and fixing of collector tube (H2)...........................................................21
3.4.6 Cleaning of absorption cell .................................................................................22

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3.4.7 Cleaning of joints etc. .........................................................................................23
3.4.8 Procedure for lowering blank value of collector tube ..........................................24
3.4.9 Adjustment of optical system..............................................................................25
4. REMOVALAND FIXING PROCEDURES FOR EACH UNIT ..........................................26
4.1 Collector tube adapter...............................................................................................26
4.2 Heater H1..................................................................................................................26
4.3 Heater H2..................................................................................................................28
4.4 Gas washing bottle and dehumidifying bottle............................................................28
4.5 Cell............................................................................................................................28
4.6 Optical system unit....................................................................................................29
4.7 Mercury lamp ............................................................................................................30
4.8 Phototube preamplifier..............................................................................................32
4.9 Second collector tube................................................................................................32
4.10 Solenoid valve and activated carbon filter...............................................................33
4.11 Flow sensor.............................................................................................................34
4.12 Air pump..................................................................................................................34
4.13 Each control board..................................................................................................35
4.14 Switching power supply...........................................................................................36

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1. Outline
Before carrying out the inspection, repair or maintenance of the mercury analyzer WA-
5A, be sure to refer to this service manual.
1.1 Outline
The Mercury WA-5A is a mercury analyzer that enables the rapid measurement of the
quantity of mercury collected in a dedicated mercury collector tube in easy operations
with high sensitivity over a wide range.
A personal computer is used for operations and the processing of measurement results,
and it is possible to make various analyses such as statistical calculations.
1.2 Basic configuration of this instrument
This instrument consists of the following units:
(1) Mercury analyzer :WA-5A
(2) Data analysis/instrument control software :WA5Win
(3) Standard accessories
(4) Personal computer

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1.3 Component description of mercury analyzer
* The same contents as those in the instruction manual are described
below:
1.3.1 Front (inside of front cover)
No. Name Remark
(1) Standard gas injection port With built-in septum
(2) Collector tube heating furnace
(H1) With built-in air cooling fan
(3) Collector tube fixing port Made of fluoroplastic
(4) Electronic cooler unit
(5) Gas washing bottle Removes acid gas.
At time of atmosphere measurement:
pH 6.86 standard buffer solution (1+1)
At time of reduction evaporation: 0.1 M
NaOH
(6) Dehumidifying bottle Removes moisture.
(7) Detection unit connection port
(8) Valve for option connection (EV)
(9) Flow adjustment needle Adjust to 0.5 L/min.
(1)
(2)
(3)
(4)
(5)
(7)
(8)
(6)
(9)

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1.3.2 Rear
No. Name Remark
(1) OUTLET Exhaust gas tube connection (6 mm
OD)
(2) Main power switch
(3) Power cable connection port 100-240 VAC
(4) Fuse 100 V, 10 A or 250 V, 5 A
(5) AC OUT Power port for sample changer
* Interlocked with main switch
(6) Personal computer connection port Connected using LAN cable
(7) Serial connection port (Not used)
(8) Dry gas meter connection port
(9) Option (Not used)
(10) Sample changer (signal) Control cable connection
(11) Sample changer (power) Driving cable connection
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)

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1.3.3 Inside of top cover
No.
Name Remark
(1) Optical system unit
(2) Absorption cell (200 mm) For low range measurement
(3) Absorption cell (1 mm) For high range measurement
(4) Low pressure mercury lamp
(1)
(2)
(3)
(4)

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1.3.4 Inside of right side cover
No. Name Remark
(1) Valve V1 Switching of sampling route and
detection route
(2) Re-collection furnace (H2) With built-in air cooling fan
(3) Valve V2 Switching of detection route and
bypass route
(4) Valve VA H2 bypass at time of H1 direct
sampling, such as that for LPG
(5) Air pump
(6) Flow adjustment needle Adjust to 0.5 L/min.
(7) Flow sensor For flow measurement
(8) Activated carbon for carrier
gas For carrier gas purification at time of trans sampling
(9) Activated carbon for carrier
gas For carrier gas purification at time of measurement
(10) Activated carbon for
exhaust gas For removal of mercury in measurement exhaust gas
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)

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1.3.5 Inside of left side cover
No. Name Remark
(1) Main board
(2) SSR1 For H1 control
(3) SSR2 For H2 control
(4) Power supply board for optical
system
(5) Power supply board for
electronic cooling
(6) Power supply board for main
board
1.4 Readers for whom this service manual is intended
This manual is for technicians who have received suitable training and are in charge of
on-site service activities or inspection, repair or maintenance in the factory.
(1)
(2)
(3)
(4)
(5)
(6)

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2. Safety
To secure safety, refer to the following:
2.1 Meanings and explanations of symbols
A caution is described to prevent an accident that involves a
serious injury or a death.
A caution is described to prevent an accident that involves a
slight injury or physical damage.
2.2 Cautions concerning installation
- To prevent an electric shock, be sure to connect a ground wire.
- To prevent an electric shock and a fire, check the power cord and plug and
make sure whether there is any damage or not.
2.3 Cautions concerning maintenance
- Cut off the power supply before starting maintenance work, or you may get an
electric shock.
- Turn off the power switch and then make sure that the heater has been cooled
before starting the maintenance work for the heater unit, or you may get a
burn.
- Take care when touching a glass component. If it is broken, you may get
injured.
- Be sure to drain liquid left in the drain tank after the end of operations. Before
draining the liquid, make sure that the power switch has been turned off.
Warning
Caution
Warning
Warning
Caution

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3. Maintenance
* The same contents as those in the instruction manual are described below:
To keep the instrument in the normal condition, refer to the contents concerning inspection,
repair and maintenance.
3.1 Inspection items
3.1.1 Daily inspection
Inspection before start of work
Inspection
item Inspection standard Measures against abnormality
Gas washing
bottle There shall be no dirt. Cleaning
Status Shall not be “OFF-LINE”. Checking of cable
connection
and port
Instrument
check Shall be completed normally. Message check
Measurement
method The setting to be used shall be set in the system setup. Change the setting using “configuration
setup” - “System
setup”.
Errors and
warnings No error or warning message shall be displayed after the completion of the
countdown.
Checking at time of measurement
Item Standard Measures against
abnormality
Blank value When purge measurements are made
repeatedly, the “HEIGHT” value on the
“LOW” side shall be 0.0002 or less.
Continual blank
measurements or
cleaning of line
Calibration
curve When a calibration curve is prepared using standard solutions, the correlation
coefficient shall be 0.9990 or more.
Replacement of collector
tube or cleaning of line
Sensitivity The gradient of the calibration curve
shall be within +/-30% of the value at
the time of the delivery.
Replacement of collector
tube or cleaning of line
History A blank value immediately after the
measurement of the standard gas shall
be 2% or less of the previous quantity of
mercury.
Cleaning of gas washing
bottle or replacement of
mercury collector tube
Precision The measurement value of the standard
gas after the measurement of a real
sample shall be within +/-5%.
Consideration of method
or quantity of samples

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3.1.2 Yearly inspection
Yearly inspection
Inspection item Inspection standard Measures against
abnormality
Mercury collector
tube
There shall be no dirt on the
quartz tube or no discoloration of
the quartz wool.
Replacement of mercury
collector tube
Absorption cell There shall be no dirt. Disassembling cleaning or replacement of absorption
cell
Flow rate There shall not be a variation of 0.02 L/min. or more in the flow
rate.
Needle cleaning or pump
replacement
Detector output
(Ref) Shall be 4+/-0.5 V on the maintenance screen of WA5Win.
Wiping of dirt on lamp, lens,
etc.
Adjustment of optical system.
Detector output
(Sig1, Sig2) Shall be 4+/-0.5 V on the maintenance screen of WA5Win.
Cleaning or replacement of
absorption cell unit. Wiping of
dirt on cell window and
phototube.
Activated carbon
filter There shall be no breakage or discoloration. Replacement
Air pump
There shall be no abnormal
sound. It shall be possible to
adjust the flow rate to 0.5 L/min.
at the time of the instrument
check.
Replacement
Electronic cooler Shall be the room temperature
minus 8°C or less. Repair

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3.2 Errors and warnings
After an error occurs, it is impossible to restart a measurement unless the cause of the error
is removed and the main unit is turned on again or “Run” - “Reset” on the menu are
executed.
（１） Warning messages
Message Contents and measures
STAND-BY xx:xx Displayed for 20 minutes after the instrument is
turned on.
Since the heaters and optical system are unstable
during the countdown, measurement data is not
reliable.
Close the door of TC-WA.
(Only when TC-WAis connected) Displayed if the door is open when the TC-WAtries to drive a component.
When the door is closed, the process is restarted.
（２） Error messages - Category 1
Error
code
Message Contents and measures
01 A/D FULL
The voltage of theA/D
converter of the optical
system exceeds the preset
value.
Issued if any voltage of SIG1, REF and SIG2 is 5 V or
more.
Possible causes are an increase in the light quantity of
the lamp, an increase in the sensitivity of the phototube,
and an abnormality in a circuit.
If the error persists even after the adjustment of the
optical system described before is made, contact us.
02 LAMP BROKEN
The light quantity of the lamp
(REF voltage) decreases
below the preset value.
Issued if the “REF” voltage is 0.5 V or less.
Possible causes are the deterioration of the lamp and
an abnormality in the phototube to correct the light
quantity or in a circuit.
If the error persists even after the adjustment of the
optical system described before is made, contact us.
03 CELL DARK
Absorption cell is soiled.
Issued if the absorption cell is dirty and the voltage ratio
of “REF” to “SIG1” is 3 or more. Clean the absorption
cell.
04
MOTOR ALARM(PUMP) The alarm is output from the
IC for driving air pump.
Issued if the IC to drive the air pump is abnormal.
If the error persists even after the instrument is
restarted, contact us.
06 COOLING ERROR(H1)
FAN1 may not be running. Issued if the temperature of the H1 is 150
°
C or more at
the end of the cooling. The fan may not be operating or
the cooling time may be short.
07 COOLING ERROR(H2)
FAN1 may not be running. Issued if the temperature of the H2 is 300
°
C or more at
the end of the cooling. The fan may not be operating or
the cooling time may be short.
08 COOLING ERROR(H3)
FAN1 may not be running. Issued if the temperature of the H3 is 150
°
C or more at
the end of the cooling. The fan may not be operating or
the cooling time may be short.

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09 HEATER BROKEN(H1)
The temperature of H1
does not rise.
Issued if the temperature of the H1 is not 400
°
C or
more at the end of “TRANS”.
If the error reoccurs after the instrument is turned off
and restarted, contact us.
10 HEATER BROKEN(H2)
The temperature of H2
does not rise.
Issued if the temperature of the H2 is not 400
°
C or
more at the end of a measurement.
If the error reoccurs after the instrument is turned off
and restarted, contact us.
20
FLOW ERROR Flow rate is not enough.
Issued if the flow rate decreases to 0.2 L/min. or less
during a measurement.
Make sure that
the pump is operating and that any tube
has not been disconnected.

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(3) Error messages - Category 2
When the TC-WA is connected:
Error
code
Message Contents and measures
11 HEATER BROKEN(H3)
The temperature of H2 does not
rise.
Make sure that TC-WA is turned
ON.
Issued if the temperature of the H3 is not 400
°
C
or more at the end of “TRANS”.
Check the power cable and switch of the TC-
WA. When no abnormality is found, contact us.
12 TC-WATIME OUT
ERROR(TABLE)
The operation of the table motor is
not completed.
An abnormality occurred at the time of table
driving.
Turn off the power, open the front cover and
check the inside.
If the error persists, contact us.
13 TC-WATIME OUT ERROR(LIFT)
The operation of the lift motor is
not completed.
An abnormality occurred at the time of lift
driving.
Turn off the power, open the front cover and
check the inside.
If the error persists, contact us.
14 TC-WA LIFT UP ERROR
The lift does not move up. Issued if the lift does not ascend during the operation to put the collector tube in the heating
unit.
Turn off the power, open the front cover and
check the inside.
If the error persists, contact us.
15 TC-WA NO SAMPLE
The measured collector tube does
not move down.
Issued if the measured collector tube does not
descend.
Turn off the power, open the front cover and
check the inside.
If the error persists, contact us.
16 TC-WA MOTOR ALARM(TABLE)
The alarm is generated from the
IC for driving table.
Issued if the IC to drive the table is abnormal.
If the error persists even after the instrument is
restarted, contact us.
17 TC-WA MOTOR ALARM(LIFT)
The alarm is generated from the
IC for driving lift.
Issued if the IC to drive the lift is abnormal.
If the error persists even after the instrument is
restarted, contact us.
If Error Code 11 is detected, the instrument will skip the subsequent sequence, start the
cooling process and stop its operation when the temperature of the H3 has fallen.
If any of error codes 12 through 17 is detected, the instrument will suspend a measurement
immediately and stop its operation.
（３） Error message - Category 3
When the gas meter is connected:
Error
code
Message Contents and measures
19 GAS METER ERROR Issued if the sampling pulse from the gas meter
is not detected at the time of a measurement in
the direct sampling mode.
If an error is detected, the instrument will skip the subsequent sequence and stop its
operation.

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3.3 Troubleshooting
3.3.1 Fall of sensitivity
Causes of the fall of peak sensitivity are roughly classified into three groups.
Abnormal standard gas: Leaking syringe, polluted syringe, abnormal temperature
in standard gas box
Abnormal instrument: Abnormal operation of or leak in heater or valve
* If a leak persists, disconnect the joint on the outlet side of the dehumidifying
bottle, and plug up with your finger the inlet of the tube that enters the main
unit. If the leak persists after that, there is an abnormality inside the instrument.
Open the cover and retighten the Teflon joint.
Dirty or deteriorated piping: Dirty collector tube, scrubbing liquid, joint
By injecting standard gas into various parts of the piping route, the faulty part can
be pinpointed.
Example: Disconnect the joint on the outlet side of the dehumidifying bottle, and
connect the standard gas injection port to this tube. When a measurement is made
in this condition and the sensitivity recovers, there is a problem in the route till the
dehumidifying bottle. When the sensitivity does not recover, there is a problem in
the route from the piping after the dehumidifying bottle to the absorption cell.
*If it is impossible to connect the injection port directly, connect it using a short
tube or a reducing Teflon joint.

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3.3.2 Abnormal blank value
The primary cause of a high blank value is the mercury pollution of the piping route. If the
blank value increases because of a dirty component, measurements in the low
concentration region will be difficult. Pinpoint the dirty part and clean or replace the
component.
The dirty part can be pinpointed by attaching a mercury removal filter to various parts of
the piping route and making comparison measurements. Attach activated carbon for a
filter or a mercury collector tube to various parts of the piping route using Tygon tubes or
the like, and make measurements.
* When standard gas is collected, a mercury grain may adhere to the syringe needle,
and the standard gas injection port may be polluted. Carry out an injection after wiping
the needle end using Kimwipe or the like.
3.3.3 Abnormal rise in sensitivity
Possible causes of a rise in the peak sensitivity are the following two failures:
Abnormal standard gas: Mercury pollution of syringe, low display temperature of
gas box, polluted septum in gas box
Decrease of flow between H2 and absorption cell: Leak, clogged collector tube,
abnormal pump

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3.4 Maintenance
3.4.1 Checking of leak
Make sure whether or not there is any leak in the piping because of a loosened joint or
the like. When the standard gas injection port is disconnected and the upper part of the
collector tube is plugged up with a finger to stop the carrier gas supply, the flow rate should
decrease to approximately zero.
When the flow rate does not decrease, there is a leak because of the deterioration of the
septum, a loosened joint or the like.
After the checking of a leak, shift the plugging finger slowly.
If the tube is opened abruptly, the collection agent will spread in the
piping route, and a normal measurement will be impossible.
If there is a leak, check connection parts. If the leak persists even after retightening,
disconnect each joint in the piping route and plug it up with your finger to pinpoint the
leaking part.
Caution

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3.4.2 Replacement of septum
(1) Disconnect the standard gas injection port.
(2) Remove the cap nut on the side having the septum.
(3) Replace it with a new septum.
Attach the components in the order shown in the
left figure.
3.4.3 Cleaning of gas washing bottle and dehumidifying bottle
(1) Open the front cover.
(2) Remove the collector tube and the screws fixing the
collector tube connection port.
(3) Remove the transparent board of the electronic
cooler.
(4) Remove the funnels and roller clamps of the gas
washing bottle and dehumidifying bottle.
(5) Pull out the gas washing bottle and dehumidifying bottle,
disconnect the silicone tubes and clean the bottles.
* Do not clean the silicone tubes but replace them.