Waltron 9091C User manual

EXPERTS IN WATER CHEMISTRY SINCE 1903
9091C Dissolved Hydrogen Analyzer
User Manual
Revision 2.04

2
WALTRON CUSTOMER COMMITMENT
This instruction manual is a technical guide to aid the customer in the set-up, operation,
and maintenance of their new Waltron measuring system. Waltron provides continuous
product improvement and reserves the right to make any modifications to the information
contained herein without notice.
Copyright © Waltron Bull & Roberts, LLC, 2016
All Rights Reserved
Technical questions concerning this product should be addressed to:
Waltron Technical Service Department
Flemington, New Jersey
Phone: [phone]
Fax: [phone]
www.waltron.net
Please be ready to provide the following information:
Date analyzer was purchased
Analyzer model and serial number
Recent maintenance history
Calibration slope values and detailed description of problem
Waltron’s technical expertise and extensive experience provides personalized solutions to
the water quality industry. It is Waltron’s commitment to provide the customer with
timely and accurate technical service and support.
Waltron fully expects the customer to be satisfied with the quality, performance, and cost
of this product.
If there are any questions or concerns regarding this product, please feel free to contact
Waltron at (908)-534-5100.
Thank you for choosing Waltron!
Please note the Waltron mailing and shipping address:
Waltron Bull & Roberts, LLC
25 Minneakoning Road, Suite 101
Flemington, NJ 08822

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Safety:
Please observe proper safety and handling precautions when installing, operating,
maintaining, and servicing this product. The following should be noted and adhered to:
Read and understand manual before working with analyzer.
Pay special attention to warning labels on enclosures, containers, packages
and chemicals.
Only qualified personnel should be involved in the installation, operation, and
servicing of the analyzer.
Follow safety precautions when operating analyzer in conditions of high
pressure and/or temperature.
Keep analyzer chemicals away from heat and extreme temperatures. Reagent
powders must be kept dry.
Follow all regulations and warning labels when disposing of chemicals. Do
not mix chemicals.
To obtain analyzer safety information or Safety Data Sheets (SDS), please contact
Waltron or visit the website at www.waltron.net .

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Warranty Agreement
If, within one year from the date of shipment, the customer experiences any equipment
defects or is not satisfied with the analyzer manufacturing, Waltron will repair, or at its
option, replace any defective part(s) free of charge. This warranty requires that the
defective part(s) be returned to Waltron with shipping charges prepaid.
At Waltron discretion, a Technical Service Specialist may be sent out to repair or replace
the defective part(s) on location. Traveling time and expenses of the Technical Service
Specialist is at the customer’s expense.
Equipment sent to Waltron must be appropriately packaged and the following
information must be provided prior to returning to Waltron:
The Return Authorization (RA) number assigned to the customer by the
Waltron Technical Service Department
Customer name, address and department
Name and telephone number of the individual responsible for returning
items for repair
Brief problem description
Ship to Waltron service center:
Waltron Bull & Roberts, LLC
25 Minneakoning Road, Suite 101
Flemington, NJ 08822
The Waltron Warranty Agreement:
Covers expendable sensors for one month after shipment and reusable
electrodes for six months after shipment.
Does not apply to damages occurred during shipping.
Warranty will be nullified if goods have been used for purposes other than
those for which they are intended or if any seal has been removed, broken
or tampered with or if the Waltron trademark or serial number has be
removed, defaced, or altered.
Does not cover expendable supply items such as reagents, tubing and
electrolytes.
Does not cover misuse or mistreatment by the user.
Does not cover previous repair or alteration by unauthorized individuals.
Waltron does not assume responsibility for contingent liability through alleged failure or
failures of products or product accessories.

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Checklist of Materials
In order to ensure customer satisfaction, Waltron does its best to provide adequate and
timely packaging and shipping services. Please perform the following after receiving a
shipment:
Inspect all shipping containers upon receipt and record any visible damage. If
there are any outward signs of damage, please retain all containers and
packages for inspection by carrier. Please retain all packing material so that it
can be used for future moving and shipping needs.
Check all items received against those on the packing list. Chemicals are
usually shipped in a separate package and will be itemized accordingly.
Verify that the number of packages received agrees with the packing list and
shipping papers.
Notify both Waltron and the carrier if any problems occur.
Important Notice:
All analyzers are inspected and tested prior to shipment.
In normal use, the unit should require only minor maintenance and should
operate correctly and without fault over a long period of time.
Please note that if electronic components need to be replaced, it may be
necessary to adjust and/or calibrate the analyzer.
Failure to carry out correct maintenance procedures may result in
inaccurate analyzer readings.

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Table of Contents
1INTRODUCTION .................................................................................................... 7
1.1 AREAS OF APPLICATION.............................................................................. 7
1.2 DESCRIPTION OF DEVICE............................................................................. 8
1.3 THE MEASURING SYSTEM......................................................................... 10
1.4 BLOCK DIAGRAM OF SENSOR SYSTEM.................................................. 11
2INSTALLATION.................................................................................................... 12
2.1 DELIVERED PARTS....................................................................................... 12
2.2 ACCESSORIES................................................................................................ 12
2.3 TECHNICAL DATA........................................................................................ 13
3OPERATING PROCEDURES.............................................................................. 14
3.1 PRINCIPLE OF MEASUREMENT................................................................. 14
3.2 CALIBRATION VIA ELECTROLYSIS......................................................... 15
4START-UP .............................................................................................................. 16
4.1 MENU STRUCTURE ...................................................................................... 16
4.2 PREPARING TO MEASURE.......................................................................... 18
4.3 CHOICE OF OPERATING PARAMETERS .................................................. 18
5MEASURING MODE............................................................................................ 20
5.1 OPERATING CONDITIONS .......................................................................... 20
5.2 ANALYZER CALIBRATION......................................................................... 20
6MAINTENANCE.................................................................................................... 21
6.1 CLEANING OF ELECTRODES ..................................................................... 21
6.2 CLEANING OF CELLS................................................................................... 22
7TROUBLESHOOTING......................................................................................... 22
8SPARE PARTS AND ACCESSORIES ................................................................ 23

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1INTRODUCTION
1.1 AREAS OF APPLICATION
The Waltron 9091C Dissolved Hydrogen Analyzer is used for the automatic, continuous
measurement and control of hydrogen concentration in aqueous solutions. Examples of
the applications of the unit include the determination of residual hydrogen concentration
in boiler feedwater in power plants, the monitoring of hydrogen concentration in the
primary loop of a nuclear power plant, the monitoring of hydrogen concentration during
the denitrification (removal of nitrate NO3) of drinking water, or the indication of the
hydrogen concentration during the catalytic reduction of oxygen on noble metal surfaces
in water treatment plants etc. The measuring range is between some µg/l (trace areas) up
to saturation level mg/l range.
The hydrogen in a water/steam loop of a power plant is mainly produced by the reaction
between iron and water or steam. Thus the hydrogen concentration gives quantitative and
qualitative evidence of the rate of corrosion and the buildup or deterioration of the
protective oxide layer inside pipes and boiler tubes. The hydrogen concentration ranges
between a few µg/l (normal operating conditions) and several hundred µg/l during the
start-up.
In the primary loop of a nuclear power plant the hydrogen should reduce or mitigate the
oxygen which is produced by radiolysis. As a result the electro-chemical corrosion
potential (ECP) of the tube material is reduced. In nuclear power plant applications,
hydrogen is added to scavenge oxygen or recombine with the oxygen that is produce by
radiolysis. In the pressurized water reactor (PWR) primary loop, hydrogen is measured
in the range 25-50cc/kg. Hydrogen in boiling water reactors (BWR) feedwater and
reactor coolant is measured in ppm’s. Hydrogen in feedwater is typically 0-2ppm and
hydrogen in reactor coolant water will vary between 0.1-0.5ppm.
The dissolved hydrogen analyzer can also be used in drinking water applications for the
denitrification of drinking water. The denitrification is based on the process in which
hydrogen is added to nitrate polluted water. The contaminated water flows through a
solid bed reactor filled with a noble metal catalyst. In result, water and nitrogen are
produced.
The catalytic reduction of oxygen is based on the reaction between dissolved oxygen in
water and hydrogen in the presence of a noble metal surface (oxyhydrogen gas reaction).
Typical applications for oxygen free water are in breweries, the beverage industry and in
the preparation of boiler feedwater in power plants.
It is important for the correct operation of various processes to dose the exact amount of
hydrogen.

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1.2 DESCRIPTION OF DEVICE
The Waltron 9091C Dissolved Hydrogen Analyzer measures reliably and quickly the
hydrogen concentration in aqueous media from the trace areas (<10,0 µg/l) up to
saturation concentrations of higher than 1600 µg/l under normal conditions.
The Waltron 9091C Dissolved Hydrogen Analyzer can be divided into two primary
function parts. The first is the electronic component which consists of the display and
input elements as well as the measuring data collection and data processing elements.
The second is the analytical component which is composed of the inlet valve, filter
device and salt cell which serve the sample and probe preparation. The measuring device
is situated together with the calibration cell, the measuring cell and the flow measuring
device. The measuring cell is joined with the temperature sensor and the reference cell
with its reference electrode.
For the measurement of the dissolved hydrogen (molecular hydrogen H2) the sample
flows through the components of the device which relate to the sample and probe
preparation and through the calibration cell into the coaxial measurement cell (grooved
measurement cell) passing by the platinum measuring electrode. The hydrogen
measurement reaction takes place due to the potential for hydrogen oxidation in the
boundary layer (interphase) between the electrode surface and sample medium.
The analyzer features automatic in-line calibration. A stainless steel electrode is used in
the calibration process. This electrode produces a known amount of H2 by electrolysis.

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The fully automatic calibration is activated with the push of a single button. As no other
external calibration devices or procedures are required, it is not necessary to shut down
the operation during the calibration. This sturdy and reliable measurement system makes
it possible to operate very accurately, even under extremely harsh operating conditions.
Waltron 9091C Dissolved Hydrogen

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1.3 THE MEASURING SYSTEM
Measuring cell Calibration cell

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1.4 BLOCK DIAGRAM OF SENSOR SYSTEM

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2INSTALLATION
2.1 DELIVERED PARTS
2.2 ACCESSORIES
1. 100 ml KCl-solution
2. 1 kg granular marble
3. 1 test tube brush
4. 1 cleaning material
5. 1 power cable
6. 1 recorder cable
7. 1 pocket (option)
8. 1 sample line (option)
9. 1 software for digital measuring (option)
White
→
0/4…..20 mA +
Brown
→
0/4…..20 mA -
Green
→
Limit (low)
Yellow
→
Common
Gray
→
Limit (high)
100
185
150
Plug Arrangement Rear
Main
Connection
Digital
Output
Sensor
Connection
Analog
Output
Color Code Analog Output
138
WALTRON

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2.3 TECHNICAL DATA
Measurement principle:.........
microprocessor based, potentiostatic three electrode system
Calibration:............................
build-in, single button operation
Auto-calibration:....................
option
Measuring range:
Measuring group I:................
0,0..........500,0 µ g/l
range selectable between 20....500 µg/l
Measuring group II:...............
0,00........20,00 mg/l
range selectable between 4....20 mg/l
Auto-changing-range:............
option
Analog output:.......................
0(4)............20 mA; shunt max. 500 Ohm
Digital output:........................
serial interface RS 232
Data logging:.........................
option
Limit:.....................................
power relay
Alarming:...............................
power relay; Flow and Calibration
Measuring electrode:.............
platinum
Counter electrode:.................
stainless steel 1.4571 (314)
Reference Electrode:.............
Ag/AgCl in saturated KCl-solution
Calibration electrode:.............
stainless steel 1.4571 (314)
Response time t90:................
30 sec
Probe conductivity:................
≥ 10 µ S/cm; (if conductivity is less a salt cell is required)
Ambient temperature:............
0.....+55 °C
Sample temperature:.............
0.....+60 °C
Sample pressure:.................
≤ 8 bar (116 psi)
Sample flow:........................
5 l/h ......15 l/h
Sample fittings:...................
tube fittings for tube ∅6 mm
Error limits:............................
± 3%
Protection class:.....................
IP 54
Color:.....................................
basic parts RAL 7035; front and rear parts RAL 7024
Voltage:..................................
100...240 VAC, 50/60 Hz
Power consumption:...............
10 VA

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3OPERATING PROCEDURES
3.1 PRINCIPLE OF MEASUREMENT
The new patented 9091C Dissolved Hydrogen Analyzer electrochemical hydrogen sensor
functions in a potentiostatic mode with an open three-electrode system. The measuring
electrode is made of solid titanium, coated with platinum. The counter electrode is made
of stainless steel and the reference electrode of silver/silverchloride. The use of an open
measuring electrode means, that there is a direct contact between the sample and the
measuring electrode. A membrane is not required.
For the measurement of dissolved molecular hydrogen (H2), the fluid medium flows into
the coaxial measurement cell between the platinum measuring electrode and counter
electrode. If the measuring electrode has reached the correct potential, hydrogen is
oxidized in the interphase boundary layer. The electrochemical reaction may be
represented qualitatively as:
H2+ 2H2O 2H3O+ + 2e-
The characteristic potential for this reaction- the potential at which hydrogen oxidation
occur in preference to other competing reactions- is measured by holding the potential of
the measuring electrode steady with a potentiostat and comparing the value with the
value of the reference electrode. Under these conditions the rate of the electrochemical
reaction is limited by the rate of diffusion of hydrogen molecules to the electrode. As
long as we remain within this ‘diffusion-limiting-current’ area, the electrochemical cell
delivers an electric current, whose size depends linearly on the concentration of dissolved
hydrogen. This current, which is measured by the instrument’s electronic processing unit,
is known as the diffusion-limiting current, Idiff:
cH2= k ·diff
This diffusion-limiting current depends mainly on the mass transport of the
electrochemically active components, and hence on the hydrodynamics in the measuring
cell. It therefore changes significantly with the temperature and flow rate through the
measuring cell. In practice the flow rate and temperature vary over wide ranges, but the
instrument corrects for these changes using empirical correlations.
A second important influence on the measurement is the condition of the electrodes. In
particular, the adsorptive and oxidative state of the electrode surface layers. This is
independent of the flow conditions. It depends instead on the voltage between the
electrode and the electrolyte, and on the material of which the electrode is made.
Appearing flow-and temperature effects of the measuring signal are recorded with the aid
of the installed flow meter and the temperature sensor and can be compensated, if it is
necessary.

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3.2 CALIBRATION VIA ELECTROLYSIS
The calibration cell contains two stainless steel electrodes, between which water is
dissociated by a constant, controlled, current. According to Faraday’s law the rate of
hydrogen production in the calibration cell is directly proportional to the current. A
constant electric current of 13.4 mA, for example, produces an increase in the hydrogen
concentration of 50 µg/l at a flow rate of 10 l/h. This rise of the output current of the
measuring cell, allows the processing unit to calibrate the system automatically. It is
important to keep the operation parameters nearly constant while running the calibration
process. Especially the basic value of the measured component must not change during
this period.

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4START-UP
4.1 MENU STRUCTURE
H2 100 μg/l
>
Please insert PIN
10.4 μg/l
0000
SET
9.1 l/h 22.2°C
Menu 01/11
Range
Range >
000.0 μg/l
SET
CalModus 3/1
ElyseCal
ElyseCal Countdown
ElyseCal >
Press > to start Elyse
6:00 min
Menu 02/11
CalModus 3/2
SubCal
CalModus >
SubCal >
000.0 μg/l
CalModus 3/3
AutoCal 1/3
AutoCal Date/Time
AutoCal >
Date/Time >
01.01.2000 12:00
SET
Menu 03/11
RangeModus 1/2
AutoCal 2/3
AutoCal Period 1/3
RangeModus >
ManRange
SET
Period >
daily
RangeModus 2/2
AutoCal Period 2/3
AutoRange
SET
weekly
Menu 04/11
I-Output
AutoCal Period 3/3
I-Output >
0..20 mA
SET
monthly
I-Output
AutoCal 3/3
AutoCal Control 1/2
4..20 mA
SET
Control >
deactivated
Menu 05/11
Limit
AutoCal Control 2/2
Limit >
000.0 μg/l
SET
activated
Menu 06/11
FlowCal
FlowCal Volume
FlowCal Volume
FlowCal >
Press > to start
60 sec
000.0 ml
SET
!!Caution!!
Parameter 1/2
Kd
Menu 07/11
You enter a site
with critical content
Kd >
1.123
Parameter
Press SET to enter
Parameter 2/2
K
K >
1.100
continued

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from previous
Menu 08/11
Logging 1/4
Logging Info
Logging >
Info >
Logging active
01.01.00 12:00
000011 entries
Logging Info
Logging stopped
01.01.00 12:00
No entries
Logging 2/4
Logging Interval 1/5
Interval >
10 sec
SET
Logging Interval 2/5
30 sec
SET
Logging Interval 3/5
1 min
SET
Logging Interval 4/5
2 min
SET
Logging Interval 5/5
5 min
SET
Logging 3/4
Logging Control
Control
Press > to stop logging
Logging Control
press > to reset
Press > to continue or
!!Caution!!
SET to restart logging
Old data are lost
Logging 4/4
LogDownload
Download >
Data acquisition spped
Menu 09/11
Date/Time
Date/Time >
01.01.2000 12:00
SET
Menu 10/11
Service 1/5
Service >
For service only
Menu 11/11
New PIN
Repeat PIN
Change PIN >
0000
SET
0000
SET

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4.2 PREPARING TO MEASURE
Before you start measuring you my perform the following procedures.
1. The electrical power supply has to be connected according to the local power
authority guidelines with the terminal box, with witch the connectors to the
0(4)...20 mA analog output (see the circuit diagram on the cover plate) should be
combined.
2. The reference cell must be filled with KCl solution. The reference cell must be
removed from the measuring cell by unscrewing the reference cell. Take out the
reference electrode and fill up the KCl solution to the level of about the beginning
of the external threading. Make sure that no air bubbles develop near the
diaphragm. Tap the cell gently if necessary. Remove any surplus of the KCl
solution and reinsert the reference electrode. Make sure that the installation of the
O-ring is correct.
3. If the probe has a conductivity of ≤ 10 µS/cm, the salt cell must be filled with
granular marble (calcium carbonate CaCO3). To do this unscrew the cover and
pour the granular marble carefully into the large cavity.
4. The probe tube is connected with tube fittings to the inlet valve. The outlet line is
placed at the measuring cell exit with a hose having a 5 mm inside diameter.
4.3 CHOICE OF OPERATING PARAMETERS
Before starting measurement, set your operating parameters. With the keys at the front
site you can move through the menu. To enter the menu, press key and insert your
code number (Pre setting: 0000; see page 17). With the keys and you move one
step in the vertical direction up or down and also increase or decrease numbers. With the
key SET you confirm chosen parameters, with the key ESC you jump back one step in
the horizontal direction with no effect.
If a > sign is displayed, you can go with the key right ahead in a sub-level.
The menu consists of eleven levels. You find your present position on the right top of the
display.
1st Menu level Range > shows range settings. The value is corresponding to the
maximum analog output currant of 20 mA. Press key and make your choice by setting
digit for digit and press the adjacent key SET. Your range is now selected and the
indication jumps one step back in the Menu.
2nd Menu level shows the calibration settings named CalModus >. Press key to jump to
the sub-level CalModus > which consists of three sub-levels called: ElyseCal >, SubCal

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> and AutoCal >. (option only). With the key you can go ahead. With the key you
will release the electrolytic calibration if you start from position ElyseCal >. From
SubCal > you are setting the present hydrogen concentration digit for digit, finally push
key SET.
3rd Menu level Range Modus > gives you the choice between ManRange (range which is
setting in 1st level only) and AutoRange (automatic changing range which has double
value of ManRange >)(Option only).
4th Menu level I-Output > sets the analog output current 0(4)...20 mA.
5th Menu level Limit > allows limit settings. There exists a switch hysteresis of 10% of
the chosen limit.
6th Menu level FlowCal > enables flow meter calibration (see Section 7).
7th Menu level Parameter > shows operation parameters Kd (flow) and k (calibration).
Attention: Only reading parameter.
8th Menu level Logging > is the data logging function (Option only).
9th Menu level Date/Time > allows date settings.
10th Menu level Service > is for service only.
11th Menu level ChangePIN > gives you the possibility to change your PIN number.
Attention: lost PIN numbers can only activated by the manufactures.

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5MEASURING MODE
5.1 OPERATING CONDITIONS
For an accurate measurement of hydrogen the probe’s environment must fulfill certain
conditions regarding conductivity, flow, temperature and pressure.
The probe conductivity must be 10 µS/cm; otherwise the salt cell must be
refilled (see also Section 4.2).
The flowrate has to be between 3 l/h and 18 l/h (The optimal flowrate is about 10
l/h).
The temperature of the sample should range between 1 °C and 60 °C.
The pressure to which the probe should be subjected at least 400 mbar and may
not exceed 8 bar. Operating conditions outside this range require either a probe
pump or a pressure reducing valve.
Connect the probe line on the fitting tube of the inlet valve. Adjust the flow very
carefully and slowly. You have to make sure that no sudden pressure push occurs and you
should verify that all air bubbles in the tube system rinse out. To help the bubbles to rinse
out, open and close quickly the inlet valve several times.
Attention: Make sure that the plugs stay dry.
5.2 ANALYZER CALIBRATION
After the hydrogen analyzer is installed and the medium flows through the analyzer the
calibration can be performed. The first calibration should take place after letting the
sample flow, for approximately 30 minutes. During the calibration the operation
conditions should not change.
1) You are in the mode for hydrogen measurement and have pressed key and insert
your PIN number. Select ElyseCal > in the menu (only for hydrogen or oxygen
measurement). You start the calibration procedure with key . The display indicates:
Thereby a countdown runs; beginning at 6:00. After the calibration time of 6 minutes is
over, the calibration mode changes automatically to the measuring mode and the
microprocessor calculates the current sensitivity of the measuring electrode and gives the
electrode a k-Factor. This k-Factor is displayed in the menu Parameter > (7th level).
ElyseCal Countdown
6:00 min