Modern Water OVA 7000 User manual

.
OVA7000
ON-LINE HEAVY METALS ANALYSER
ROUTINE SERVICE MANUAL
V1.5

Copyright © 2015 Modern Water Monitoring Ltd. All rights reserved.
Modern Water Monitoring Ltd.
15 –17 Cambridge Science Park
CAMBRIDGE CB4 0FQ
UNITED KINGDOM
Email: [e-mail]
Web address: www.modernwater.com
Telephone: [phone]
P/N. 210-071-1.5

OVA7000 Routine Service Manual V1.5 3
Contents
1Introduction 5
1.1 OVA7000 .................................................................................................................................................. 5
1.2 OVA7000dual ........................................................................................................................................... 6
1.3 OVA7000 Set Top Box............................................................................................................................. 6
1.4 Typographical Conventions....................................................................................................................... 6
2Getting Started 7
2.1 Powering Up and Communicating with the OVA7000............................................................................. 7
2.2 Priming Reagent Lines.............................................................................................................................. 9
2.3 Initiating OVA7000 Operation.................................................................................................................. 9
2.4 Stopping OVA7000 Operation.................................................................................................................. 9
2.5 Powering Down the OVA7000 ............................................................................................................... 10
3Weekly Maintenance 11
3.1 Maintenance Popup................................................................................................................................. 11
3.2 Reagent Replacement and Monitoring .................................................................................................... 12
3.2.1 Replacing Reagent during a Run.................................................................................................. 12
3.3 Pump Calibration..................................................................................................................................... 12
3.3.1 Pump Calibration Procedure ........................................................................................................ 13
3.4 Working Electrode Maintenance............................................................................................................. 14
3.4.1 Polishing procedure...................................................................................................................... 14
3.5 Filter Maintenance................................................................................................................................... 14
3.5.1 Filter Pump Tubing ...................................................................................................................... 15
3.5.2 Filter maintenance procedure....................................................................................................... 15
4Checklist Sheet 16

OVA7000 Routine Service Manual V1.5 4
Figures
Figure 1. OVA7000 and OVA7000dual, shown with optional OVA7000 Set top Box ......................... 5
Figure 2. Ultra VNC Viewer Screen ...................................................................................................... 7
Figure 3. OVA7000 Main Screen........................................................................................................... 8
Figure 4. OVA7000 Run Screen ............................................................................................................ 8
Figure 5. Maintenance popup menu ..................................................................................................... 11
Figure 6. Maintenance category submenu............................................................................................ 11
Figure 7. OVA7000 Calibrate Screen................................................................................................... 13
Figure 8. Filter pump cover removal.................................................................................................... 15
Figure 9. Filter pump tubing replacement ............................................................................................ 15
Figure 10. Filter assembly.................................................................................................................... 15
Figure 11. Service Checklist Sheet....................................................................................................... 17

OVA7000 Routine Service Manual V1.5 5
The On-Line Voltammetric Analyser (OVA) has been designed to enable reliable continuous on–line monitoring
of selected heavy metals. The robust and versatile OVA7000 is suitable for use in a variety of industrial
applications. The manuals supplied with this instrument are:
Routine Service Manual (this manual). This is a very short manual for maintenance personnel to easily reference
the weekly / fortnightly routine maintenance and inspection procedures.
Operation Manual. This is a more detailed manual providing a general overview and more detailed information on
the generally important topics of instrument methodology and systems.
Reference Manual. Provides highly detailed information on instrument operation and configuration.
1.1 OVA7000
The OVA7000 On-Line Trace Metals Analyser has been designed for automated monitoring of trace metals
(such as Cd, Pb, Cu, Hg, & As) in aqueous solutions using the electrochemical techniques of Anodic and
Cathodic Stripping Voltammetry. In some instances the monitored sample may require filtration, acidification or
UV digestion before it can be analysed. All these options are available and can be incorporated into the fully
automated analysis cycle.
Figure 1. OVA7000 and OVA7000dual, shown with optional OVA7000 Set top Box
The OVA7000 cabinet is divided into two compartments accessed by individual lockable doors. Sample and
other required reagents are supplied to the analytical cell as required by in built peristaltic pumps.
1Introduction
Analytic
Compartment
Optional
Reagent
Compartment
Optional
Set Top Box

OVA7000 Routine Service Manual V1.5 6
1.2 OVA7000dual
The OVA7000 is also available as a dual analytical cell unit. Each cell has its own display, access screen, and
application software. The first cell controls the shared preparation cell and tells the second cell when to run.
Accordingly the first cell is referred to as the “master”, and the second cell as the “slave”.
Remotely the VNC Client can show the master and slave access screens as two separate windows side by side.
Locally, if a monitor or Set Top Box is attached, the access screens can be switched by pressing the front or rear
VGA select button. The master screen is identified by the green start button, with blue window boarders and
taskbar. The slave screen is identified by the orange start button, with grey window boarders and taskbar.
Information specific to the OVA7000dual in this manual is printed in blue text.
1.3 OVA7000 Set Top Box
The OVA7000 Set Top Box is a purpose built touchscreen monitor that sits atop the OVA. This allows users to
conveniently interact with the OVA application and OVA equipment together. The Set Top Box can be used
without a physical keyboard by clicking the onscreen keyboard icon on the quick launch taskbar at the
bottom of the screen.
1.4 Typographical Conventions
The following kinds of formatting in the text identify special information.
Convention
Type of Information
Triangular Bullet()
Step-by-step procedures. You can follow these
instructions to complete a specific task.
Emphasis
Use to emphasize the importance of a point.
Special Bold
Items you must select, such as menu options,
command buttons.
Caution:
Important information.
Note:
A tip or an item of note.
Blue text OVA7000 Dual Cell specific information

OVA7000 Routine Service Manual V1.5 7
This manual is a simple step-by-step guide to routine servicing of the OVA7000. For more detailed information
and instructions on more advanced functions, please refer to the other manuals supplied with the instrument –the
OVA7000 Operation Manual and the OVA7000 Reference Manual.
The majority of OVA maintenance operations require user interaction with the OVA Application software while
the user also interacts with the OVA unit itself. The optional OVA7000 Set Top Box (or VGA monitor with a
mouse) is the easiest solution; otherwise a laptop computer with VNC Viewer software will need to be
connected.
The OVA7000 Set Top Box is a touchscreen monitor without a physical keyboard, however a virtual onscreen
keyboard is accessible by clicking on the icon on the quick launch taskbar at the bottom of the screen.
2.1 Powering Up and Communicating with the
OVA7000
Caution: Always ensure that both inner and outer reference chambers are full, and there is liquid covering the
working electrode inside the cell. Failure to do this may cause an alarm condition, or damage to the electrode.
To power up and communicate with the OVA7000.
1. Switch on the external supply power to OVA7000 and press the power button. The power button will then
glow green to indicate that power is being supplied, and the OVA7000 will take a few minutes to start up.
2. After the front display shows the System Ready message, establish a network connection using a laptop or
PC if one doesn’t already exist (see Networking section 4.3 of the OVA Reference Manual).
3. Log into the OVA7000 via the remote desktop connection, using the laptop or PC running Ultra VNC
Viewer. Enter the IP address of the OVA7000 (and the port number if the network requires) and press
connect. After establishing contact with the OVA7000’s Ultra VNC Server the Viewer will be asked to
enter a password.
Figure 2. Ultra VNC Viewer Screen
2Getting Started

OVA7000 Routine Service Manual V1.5 8
The Ultra VNC viewer is freely available from http://www.uvnc.com/. Alternative remote viewers exist
for Android and iOS platforms. For more information on VNC see section 4.4 of the OVA7000
Reference Manual.
Once the remote desktop connection is established, the OVA7000 application software will show the
Main screen as shown below.
Figure 3. OVA7000 Main Screen
4. Click the Log In button, located in the bottom right section of the OVA7000 Main Screen, and enter
your username and password.
5. Click the Run button, located in the top right section of the OVA7000 Main Screen, to enter the Run
screen.
Figure 4. OVA7000 Run Screen
The OVA7000 is now ready for use but is not yet operational.
6. To begin OVA7000 operation, follow the instructions in sections 2.2, Priming Reagent Lines and 2.3,
Initiating OVA7000 Operation.

OVA7000 Routine Service Manual V1.5 9
2.2 Priming Reagent Lines
Before OVA7000 operation, all tubing lines should be full of fresh reagent and free of air bubbles. To ensure
this, the lines need to be primed.
Prime reagent lines.
1. Ensure all reagent lines are sitting in full reagent containers, the ends have tube weights and the tubes
are fully inserted into the bottles.
2. Select the Manual tab on the Run screen.
3. Select the drain pump for each cell and leave it running to drain the cell and to prevent overflow. Click
on the pump icon for each pump to be primed. When on, the pump will turn and the pump icon will
change from red to green. All necessary pumps can be primed simultaneously if required, except for the
rinse which has a much higher flow rate and so should be done by itself.
4. When a line is full of reagent & free of air bubbles, click its icon again to turn the pump off.
2.3 Initiating OVA7000 Operation
If the OVA7000 has been inactive for a significant time, the weekly (see section 3) and or 3-monthly
maintenance procedures (see OVA7000 Operation Manual) will need to be carried out before initiation.
Caution: A reference electrode that is not filled with reference electrolyte or has significant air bubbles may
cause irreversible damage to the working electrode when the Run page is entered and working electrode is
connected.
Initiate OVA7000 operation.
1. Click on the green Run Schedule button in the middle of the Run Screen.
2. If the schedule has a Plate script configured then the button will split into a blue Plate First button and a
green Run Schedule button. Select either to begin automatic operation.
The OVA7000 will now operate automatically in accordance with the method scripts activated by the Scheduling
feature of the OVA7000 software. These are described in the OVA7000 Operation Manual as they are not
routinely modified and should only be modified by suitably trained personnel.
The OVA7000dual only requires that the Run Schedule button is pressed on the master side. The master’s
schedule includes signaling scripts that will initiate a Standard or Sample run on the slave side when appropriate.
If the master’s schedule is restarted while the slave is still operating, then the slave will abandon its prior
operation when it is signaled to run a new script by the master.
2.4 Stopping OVA7000 Operation
Stop OVA7000 operation.
1. Click the Stop button in the Run screen. All activity will stop and a Drain all Cells button will appear.
2. If desired, both Analytic and Prep cells can be drained by clicking the Drain all Cells button.
3. Exit the Run screen to the Main screen by clicking the Main Menu button.
The OVA7000dual’s slave side will continue its current Standard or Sample script after the master has been
stopped. If you wish to stop the slave side entirely then you will need to do so by accessing the slave side’s own
control screen (open a second VNC window or from the Set Top Box by pressing the Select VGA button).

OVA7000 Routine Service Manual V1.5 10
2.5 Powering Down the OVA7000
It is not normally necessary to power down the OVA7000 for weekly maintenance. If it does become necessary
for any reason, follow the below procedure after stopping the OVA7000 as described above.
Caution: Selecting the “Shut down” option for the OVA7000 via a remote desktop connection will result in the
OVA7000 turning off, and an operator having to physically visit the OVA7000 to turn it back on.
However, selecting the “Restart” option for the OVA7000 via a remote desktop connection will result in the
OVA7000 restarting automatically after a few minutes, without a physical visit required.
Power down the OVA7000.
1. Close the OVA7000 software by clicking the Exit button from the Main page.
2. Shut down Windows from the Start menu in the bottom left hand corner of the screen. Select Shut Down
as with any other computer. After a minute the power to the OVA7000 can be turn off at the supply
point if desired.
Alternatively the user can restart Windows from the Start menu in the bottom left hand corner of the screen.
Select Restart as with any other computer. Power is maintained to the OVA7000 throughout a restart
operation.
Powering down the OVA7000 from the unit.
Briefly press the power button (or both power buttons for an OVA7000dual) and the OVA will initiate a
shutdown. The front display will show the “Shutting Down” message until the unit turns itself off.
Caution: Avoid pressing the power button for 4 seconds (or longer) for an immediate power down, since without
an operating system shutdown there is a small chance some data in the OVA7000 working directory may
become corrupted. An immediate power down is only required if the operating system is unable to respond
otherwise.

OVA7000 Routine Service Manual V1.5 11
Routine maintenance should be carried out when the OVA7000 is to be started for the first time after installation
or repair as well as on a regular basis. The frequency of the maintenance will be dictated by the nature of the
sample and the frequency of analysis. After one month of operation, the ideal frequency will be determined.
More frequent checks before this are advisable to ensure the OVA7000 provides accurate data.
The essential maintenance tasks are:
Ensure an adequate supply of all reagents is available.
Check the peristaltic pumps are calibrated at least every 14 days.
Clean the working electrode surface as required.
Check that the reference silver electrode has an adequate coating on it.
Check the reference electrode chamber is more than three quarters full of electrolyte and free of air bubbles.
Monitoring the peak height and position for each metal being analysed is a good indicator of how well the
OVA7000 is functioning. The peak height and position of a standard concentration of the metals will be recorded
during the initial installation. For additional information refer to the OVA7000 Operation Manual. A variation of
greater than 30% indicates a problem that should be investigated.
A weekly maintenance checklist is supplied with this manual which may be photocopied and used as a
maintenance guide and record.
3.1 Maintenance Popup
The floating Maintenance popup menu appears on
entry to the Run page if one of its Pumps,
Electrodes, or Tubing categories is red flagged for
maintenance. If the user clicks anywhere outside
it then it will disappear for an hour before
returning.
Figure 5. Maintenance popup menu
Figure 6. Maintenance category submenu
Each Pump automatically has a date recorded that indicates when it was last calibrated. For Electrode and
Tubing servicing the date is set manually by highlighting the item and the clicking Done button. The Due (wks)
column is the number of weeks from the date that the item will be red flagged for maintenance again. The user
can edit the Due Period number according to their own maintenance regime, or if it is set to zero it will prevent
the item from being red flagged (eg Drain pumps need not be calibrated).
The Wear (hrs) column shows the number of operating hours that the pump has accumulated. This number can
be used to judge the life expectancy of the pump head, as its peristaltic tubing wears. When the pump head is
replaced with a new one the Clear button is used to reset the highlighted pump.
The Update button saves any user changes made to the “maint.csv” file. This Excel readable file records the
wear and last ten service dates of all the items from all the categories.
The Cancel button exits the submenu and the popup. If the Update button wasn’t used then any changes are lost.
To bring the Maintenance popup menu back click the Maint Popup switch at the bottom of the Status and OVA
tab.
3Weekly Maintenance

OVA7000 Routine Service Manual V1.5 12
3.2 Reagent Replacement and Monitoring
Reagents can usually be replaced while the OVA7000 is carrying out an analysis providing precautions are taken
to stop air from being sucked into the reagent tubes. The OVA7000 will normally use electrolyte, standard and
cell rinse solution (normally deionised water). Other applications may also use various acid and working
electrode plating solutions.
For each application cycle it will be necessary to calculate the consumption of each of these reagents and pre-
plan their replacement. If possible, plan the replacement procedure so that it can be carried out at a set time (e.g.
Friday afternoon or Monday morning) each week.
For example, an application that uses 9.5 mL of electrolyte per sample in the voltammetry cell and runs an
analysis every 15 minutes will require 912 mL of acid per 24 hours of run time. ((24 x 60)/15) x 9.5. In seven
days of continuous running approximately 7 litres of electrolyte will be required.
It is essential that each reagent is replaced when the relevant pump is not operating. Identify the longest period in
the analytical cycle that the pump does not operate. If the time the pump is off is never less than 5 minutes, it
may be advisable to stop the OVA7000 by using the Stop button. In this way you will not inadvertently admit air
to the reagent tubes.
3.2.1 Replacing Reagent during a Run
Replacing reagent during OVA7000 operation (Run).
1. When the corresponding pump is off, carefully remove the flexible tubing from the reagent container to
be changed and place on a clean surface.
2. Refill the container with fresh reagent.
3. Re insert the flexible tubing into the container. Ensure the tubing reaches the bottom of the container.
The reagent is now ready for use.
4. Standard lines should always be purged as they pump small volumes which must nevertheless be
accurate, so that even small air bubbles can cause a significant error
Warning: If for any reason air bubbles are admitted to the tubing, the instrument will have to be stopped and
the line will have to be purged.
3.3 Pump Calibration
Calibration allows each pump to be set for accurate delivery of the required volume. This should ideally be
carried out every week, each time the pump or pump head is replaced, when the instrument has not been used for
a few weeks or when the instrument is used for the first time.
An accurate 10 mL volumetric cylinder, or digital scales with at least 0.1 gram resolution, is required. The digital
scales can be used to accurately measure water volume by zeroing the container and reading grams as mL.
Ensure access to the OVA7000 Main screen as per section 2.1, Powering Up and Communicating with the
OVA7000 on page 7. From the Main screen select Calibrate Pumps. The Calibration screen will be displayed.

OVA7000 Routine Service Manual V1.5 13
Figure 7. OVA7000 Calibrate Screen
3.3.1 Pump Calibration Procedure
Filter and UV Cycle pumps do not need to be calibrated (and will have a configured flow value of 0.0 ml/s)
Drain pumps do not need to be calibrated if their configured flow value is lower than their actual value (eg
1.0 ml/s rather than 1.4 ml/s), or if the operating scripts pump more than required (eg 13ml rather than 10ml)
Calibration procedure for all other pumps:
1. Ensure the pump inlet tube is in reagent or distilled water and that the tubing is full of liquid from the
inlet through to the outlet. Fill the pretreatment cell with sample or water.
2. Remove the pump outlet tube from the cell and insert the end of the tube into the 10 mL measuring
cylinder. Use either of the following methods to pump a volume of liquid into the measuring cylinder.
3. Start the relevant pump turning by clicking the pump icon. When the volume in the measuring cylinder
reaches about 7 or 8 mL, stop the pump by clicking on the pump icon again or pressing the “Esc” key.
Alternatively enter the number 8 next to the pump’s “Add” button on the “Pumps” tab page. When set
for “mL”(see centre top button) and “Add” clicked it will pump 8mL (according to its last calibration
value).
4. Read the pumped volume from the measuring cylinder and enter it into the pop up dialog. Press cancel
if you feel an incorrect volume was collected.
5. Check the calibration by repeating step 3 and ensure the pumped volume (displayed next to the pump
icon) matches that collected in the measuring cylinder.
6. Empty the measuring cylinder and repeat for all other pumps.

OVA7000 Routine Service Manual V1.5 14
3.4 Working Electrode Maintenance
The electro-active surface of the working electrode will not remain perfect for an indefinite period. Periodically
the electrode surface will need to be renewed.
A deterioration of the surface will usually manifest itself as a low standard peak or lack of reproducibility,
particularly on repeat analyses of a standard sample whose characteristics are known.
3.4.1 Polishing procedure
Working electrode polishing procedure.
1. Click the Stop button to stop the OVA7000.
2. Drain the cell by clicking the drain pump in the Run screen with the Manual tab selected.
3. Press Main Menu to return to the Main screen, which puts the instrument into standby mode.
4. Remove the electrode with the electrode tool supplied.
5. Rinse the electrode surface with deionised water to remove any particulates present, then wipe the
surface of the electrode with a clean tissue.
6. Open the polishing kit supplied and put 2 or 3 drops of the polishing fluid onto the polishing pad.
7. Place the electrode onto the polishing pad and gently polish the surface by moving the electrode in a
circular motion for approximately 30 seconds.
8. Rinse the electrode surface with deionised water.
Warning: Do not allow fingers to touch the surface of the electrode at any time. Grease will severely
reduce the sensitivity of the electrode.
9. Replace the electrode in the cell but do not connect alligator clip. Add a couple of mL of rinse or
electrolyte solution to the cell.
10. Restore the OVA7000 to operational mode as described in section 2.3, Initiating OVA7000 Operation
on page 9. Reconnect the working electrode alligator clip before commencing operation.
3.5 Filter Maintenance
Filter maintenance may be divided into three components per stream, each of which may be required at different
intervals.
The filter pump’s tubing lifespan is very much dependent on the OVA7000’s application. Where the filter
pump is required to run continuously it is recommended the tubing is replaced every 2 weeks. In
applications where the pump is non-continuous then the following formula can be used as a guide:
Tubing life (weeks) = 2 x 24 ÷ hours running per day
The other application dependent factor is the corrosive or abrasive properties of the raw sample fluid. If this
is an issue, then the tubing will need to be replaced regularly, irrespective of how often the pump runs. For
very corrosive sample streams this should be weekly.
The filter assembly should be cleaned as required. This may vary from weekly to monthly depending on the
level of solids in the sample.
Non-pump sample stream tubing need generally only be replaced every 3 to 6 months. This may
occasionally be more frequently required if visible deterioration of tubing occurs.
Before performing any filter related maintenance, stop the OVA7000 as per section 2.4, Stopping OVA7000
Operation on page 9.

OVA7000 Routine Service Manual V1.5 15
3.5.1 Filter Pump Tubing
Filter pump tubing replacement procedure.
1. Open the pump cover facing by undoing the 2 front screws as shown in Figure 8.
2. Insert the pump tubing as shown in Figure 9. It will be helpful to turn the pump rotor as you do this.
3. Replace the pump facing and the 2 screws.
Figure 8. Filter pump cover removal
Figure 9. Filter pump tubing replacement
3.5.2 Filter maintenance procedure
Filter maintenance procedure.
1. Unscrew the bottom of the filter assembly as shown in Figure 10.
Warning: The filter assembly will contain a considerable amount of untreated sample. If this is a
corrosive, toxic or otherwise hazardous solution, appropriate safety precautions must be taken before
opening the filter assembly.
Figure 10. Filter assembly
2. Remove the disk filter (shown in red in Figure 10) from the assembly. This will automatically expand
when removed and can easily be cleaned under a tap in most cases.
3. Re-assemble the filter assembly.

OVA7000 Routine Service Manual V1.5 16
This checklist sheet over-page should be photocopied and kept as a record of OVA7000 maintenance history.
4Checklist Sheet

OVA7000 Routine Service Manual V1.5 17
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Operator
Date
Check Reagent levels
Calibrate pumps
Polish Working Electrode
Inspect Reference Electrode
Check Reference Electrolyte
Check Stirrer operation
Check Sample Stream
Inspect filter operation
Change filter pump tubing
Date
Check Reagent levels
Calibrate pumps
Polish Working Electrode
Inspect Reference Electrode
Check Reference Electrolyte
Check Stirrer operation
Check Sample Stream
Inspect filter operation
Change filter pump tubing
Figure 11. Service Checklist Sheet