Metex 8760CLP User Manual
OPERATING INSTRUCTION MANUAL
MODEL 8760CLP
TOTAL FREE CHLORINE & pH ANALYZER
REV. 0
AquaMetrix Inc.
1245 Maple Hill Ct, Unit 7
Newmarket, ON
Canada, L3Y 9E8
Tel: (800) 742-1413
(905) 954-0841
Fax: (905) 954-0415
www.aquametrix.com
N116-58 R.0
Contents
AQUAMETRIX INC.
Contents ……………………………………………….
8760CLP Menus………………………………………
INTRODUCTION…………………………………….
General …………………………………………
Features………………………………………….
Specifications…………………………………….
INSTALLATION…………………………………….
Analyzer Mounting……………………………….
8760CLP Component Identification……………...
Analyzer Wiring…………………………………..
Sensor Mounting………………………………….
Sensor Wiring……………………………………..
Instrument Shop Test Startup……………………..
STARTUP……………………………………………..
Analyzer Startup Tests………………………….
Easy to use menu………………………………...
Remembers Where You Were…………………...
Home Base: Press Sample……………………….
Display Features…………………………………
Arrow Keys……………………………………...
AUTO and MANUAL Keys………………...……
Standby Mode…………………………………….
Output Hold……………………………………….
Edit Mode…………………………………….…...
Temperature °C or °F………………………….…
Real-Time Clock……………………………..…..
Input Damping…………………………………….
APPLICATION INFORMATION…………………..
Chlorine Chemistry……………………………..
Chlorine and the Effect of pH…………………..
Disinfectant Properties of Chlorine……….…….
8760CLP CHLORINE MEASUREMENT………….
Introduction……………………………………...
Galvanic Measuring Cell…………………….….
CHLORINE SENSOR INSTRUCTIONS………..…
Chlorine Sensor, P/N A2104034, Component
Identification…………………………………...…
Assembly of the Chlorine Sensor………………...
Inserting Chlorine Sensor in the Flow Fitting.……
Removing Chlorine Sensor from Flow Fitting……
Zero Test Technique………………………………
Monthly Maintenance……………………………..
Semi-Annual Maintenance………………………..
Chemical Cleaning………………………………..
Sensor Storage…………………………………….
CHLORINE CALIBRATION……………………….
Standardizing Chlorine……………………………
PH and Temperature impact on Chlorine…………
Manual Temperature Compensation……………...
Manual pH Compensation………………………...
pH SENSOR INSTRUCTIONS……………………...
2
3
6
7
7
8
12
12
12
13
13
13
14
15
15
16
16
16
16
17
17
17
17
18
19
19
19
20
20
20
22
23
23
23
24
24
25
27
27
27
28
28
28
29
30
30
32
32
32
33
Inserting pH Sensor into Flow Fitting…………….
Removing pH Sensor from Flow Fitting…………...
Electrode Maintenance……………………………..
Sensor Storage……………………………………...
Monthly Maintenance………………………………
Yearly Maintenance………………………………..
When to Clean Sensor……………………………...
pH CALIBRATION…………………………………...
Selecting a pH Buffer………………………………
PH Buffer Use and Maintenance…………………...
Standardizing – Single-Buffer Calibration…………
Calibrating – Two-Buffer Calibration……………...
Manual Adjustment of Offset and Slope…………...
ERROR MESSAGES………………………………….
Acknowledging an Error Message…………………
Messages for Chlorine Input……………………….
Messages for Temperature Input…………………...
Messages for pH Input……………………………..
Cautions Messages for Alarms…………………….
DISPLAY PROMPTS…………………………………
GLOSSARY……………………………………………
CONFIGURATION OF PROGRAM………………..
OUTPUT SIGNALS…………………………………..
Reversing the 4 mA to 20 mA Output……………...
Simulated 4 mA to 20 mA Output………………….
Units for Outputs…………………………………...
ALARM FUNTIONS………………………………….
Use of Relay Contacts……………………………...
Alarm Indication……………………………………
Manual Alarm Override……………………………
Delayed Relay Activation………………………….
Unit Selection………………………………………
Wiring and NO/NC Contacts……………………....
High or Low Alarm………………………………...
Deviation Alarm……………………………………
Fault Alarm…………………………………………
Using Alarms for On/Off Control………………….
TROUBLESHOOTING………………………………
Analyzer: Electronic Hardware Alignment………..
Chlorine Sensor…………………………………….
pH Sensor…………………………………………..
APPENDIX A – Enabling Security…………………...
APPENDIX B – Default Settings……………………..
APPENDIX C – Installation…………………………..
DRAWINGS……………………………………………
D4040081: Outline and Mounting Dimensions……
D5030269: Main Board Component Location…….
D5980176: Display Board Component Location…..
D5040276: Wiring Diagram………………………..
INDUSTRIAL PRODUCTS WARRANTY………….
INDEX………………………………………………….
33
33
33
33
34
34
34
36
36
37
38
39
39
40
40
41
41
42
43
44
46
47
49
49
49
49
50
50
50
51
51
51
51
52
52
53
53
54
54
56
57
59
62
63
64
64
65
66
67
68
69
1-800-742-1413 www.aquametrix.com 2
AQUAMETRIX INC.
I
8760CLP Menus
llustration 1: Menu overview
1-800-742-1413 www.aquametrix.com 3
8760CLP Menus
I
I
I
AQUAMETRIX INC.
llustration 3: Timer menu
llustration 2: Configuration menu
1-800-742-1413 www.aquametrix.com
llustration 4 Alarm menu
4
AQUAMETRIX INC.
I
I
llustration 5: Internal data log menu
llustration 6: Serial menu
1-800-742-1413 www.aquametrix.com
5
AQUAMETRIX INC.
INTRODUCTION
The model 8760CLP is AquaMetrix’s industrial quality remote operational total free chlorine and pH
analyzer, designed to provide maximum flexibility, reliability, and ease-of-use. The model 8760CLP
analyzer has been designed to include a pH input to measure sample pH for continual pH
compensation ― ideal for samples with fluctuating pH values. Temperature compensation is obtained
via a temperature sensor in the chlorine sensor.
The chlorine sensor used with the 8760CLP is a galvanic cell that is separated from the process by a
chlorine permeable membrane. As the hypochlorous acid (HOCl) in the process diffuses through the
membrane, a galvanic reaction occurs which produces a current that is proportional to the free available
chlorine concentration. An advantage of the galvanic cell is that an absolute zero measurement can be
obtained; no chlorine present equals no chlorine produced. Many manufacturers use amperometric
technology as opposed to galvanic. Amperometric cells rely on an induced voltage to produce a current.
Since this residual current is always present, an absolute measurement cannot be obtained and the HOCl
concentration measured may be artificially high. Another disadvantage of the amperometric method,
that does not affect galvanic measurement, pertains to iron coating. Polarization attracts iron ions that
may be in the process water which can cause coating of the membrane; iron deposits on the membrane
can skew the chlorine readings.
NOTICE OF COMPLIANCE
US
This meter may generate radio frequency energy and if not installed and used properly, that is, in strict accordance with
the manufacturer’s instructions, may cause interference to radio and television reception. It has been type-tested and
found to comply with the limits for a Class A computing device in accordance with specifications in Part 15 of FCC
Rules, which are designed to provide reasonable protection against such interference in an industrial installation.
However, there is no guarantee that interference will not occur in a particular installation. If the meter does cause
interference to radio or television reception, which can be determined by turning the unit off and on, the user is
encouraged to try to correct the interference by one or more of the following measures:
* Reorient the receiving antenna
* Relocate the meter with respect to the receiver
* Move the meter away from the receiver
* Plug the meter into a different outlet so that the meter and receiver are on different branch
circuits
If necessary, the user should consult the dealer or an experienced radio/television technician for additional suggestions.
The user may find the following booklet prepared by the Federal Communications Commission helpful: How to Identify
and Resolve Radio-TV Interference Problems. This booklet is available from the U.S. Government Printing Office,
Washington, D.C., 20402. Stock No. 004-000-00345-4.
CANADA
This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus set out in the
Radio Interference Regulations of the Canadian Department of Communications.
Le present appareil numérique n’ émet pas de bruits radioélectriques depassant les limites applicables aux appareils
numériques (de la class A) prescrites dans le Règlement sur le brouillage radioélectrique édicté par le ministère des
Communications du Canada.
1-800-742-1413 www.aquametrix.com
6
AQUAMETRIX INC.
General
The 8760CLP is supplied in a corrosion resistant IP65 (NEMA 4X) watertight, dust-tight case. The
analyzer measures the sensor signal corresponding to the actual chlorine with respect to the sample pH
and temperature. The analyzer digitizes the signal for maximum accuracy, conditions it and then sends
it out as a digital output and/or on 4 mA to 20 mA outputs.
The model 8760CLP comes as a complete sample conditioning system. The analyzer is mounted on a
CPVC panel with a dual flow cell containing the pH and chlorine sensors. The sample conditioning
system includes a pressure regulator valve, head tank, sample point and atmospheric drain. The only
installation requirement of the user is to mount the panel and supply plumbing to the inlet and from the
outlet. A chlorine and pH calibration kits are supplied with the unit.
Features
The model 8760CLP total free chlorine and pH analyzer has the following features:
• No reagents required: reagent based analysis typically require a separate waste outlet. Added
reagents also require time for reaction, therefore, there is usually a lag time in response. No reagents
allow for reduced stock and maintenance costs.
• No mechanical parts: since direct measurement does not require reagents to be added and sample
mixing, there is no need for additional pumps, tubing etc., which also reduces the maintenance
required.
• Immediate response without lag time: the direct measurement method used with the model 8760CLP
gives instantaneous results. By comparison, systems that use reagents require time for the sample to
react with the reagent in the sample chamber, thus introducing a lag time.
• Galvanic technology: for better calibration with absolute zero. Galvanic technology does not attract
iron to the sensor tip, therefore, the sensor requires less cleaning and maintenance.
• Easy to replace membrane.
• pH measurement and compensation for better accuracy.
• Intuitive user-friendly program that is easy to use.
• Grab sample calibration for chlorine.
• Self and sensor diagnostics.
• Two programmable 4 mA to 20 mA outputs.
• Two programmable alarms.
• Serial digital output and remote operation.
• Three level security to protect settings.
1-800-742-1413 www.aquametrix.com
7
AQUAMETRIX INC.
Specifications
Specifications
Analyzer; 8760CL
Physical Data
PROPERTY CHARACTERISTIC
Display Four LCD digits, 1.5 cm (0.6 in) displays for total free available chlorine
(tFC1) and diagnostic information (back –lit display optional)
Display Ranges Total free available chlorine (tFC1): 0.00 mg/L to 5.00 mg/L
Free available chlorine (HOC): 0.00 mg/L to 2.00mg /L
PH: 0 pH to m14 pH units.
Temperature: -5.0 °C to 105 °C (23.0 °F to 221 °F)
Keypad 8 push button entry keys
LED’S 2 alarms (A and B). 1 auto, 1 error
Analyzer
Dimensions
Panel
Dimensions
Weight 9.1 kg (20.0 lb)
Shipping
Weight
Shipping
Dimensions
PROPERTY CHARACTERISITCS
Temperature
Environment
Ratings
Electrical
Ratings
Electrical
Requirements
12.0cm (H) x 20.0 cm (W) x 7.5 cm (D)
[4.7 in (H) x 7.9 in (W) x 3.0 in (D) ]
36 cm (W) x 66cm (H) [14 in (W) x 26 in (H) ]
11.4 kg (25.0 lb)
71 cm x 41 cm x 20 cm
(28 in x 16 in x 8 in)
Environmental Data
Operational: 5.0 °C to 45 °C (41.0 °F to 113 °F)
Storage: -10 °C to 55 °C (14.0 °F to 55 °F)
Relative Humidity: 95% maximum; non-condensing
Housing: IP (Nema 4X)
Pollution Degree: 2
Installation Category: II
115/230 VAC, 0.25 A, 50/60 Hz
115/230 VAC ± 10%, 50 W
1-800-742-1413 www.aquametrix.com
8
Specifications
Analyzer 8760CL
PROPERTY CHARACTERISTIC
AQUAMETRIX INC.
Operational Data
Accuracy
Precision
Response Time 90% within 5 s (default), function of flow and temperature
Temperature
Compensation
Sample Conditions Flow: 50mL/min to500mL/min
Sample Inlet ½ in barb fitting
Chlorine: ±0.02 mg/L
PH: ±0.04 ph units
Temperature: ±0.1 C
Chlorine: ±0.01 mg/L
PH: ±0.02 pH units
Temperature: ± 0.1 °C
Damping adjust: 3 to 99’s
Automatic temperature compensation via 1000 Ω Pt RTD.
Auto: -5 °C to 105 (23.0 °F to 221 °F)
Manual -5 °C to 105 (23.0 °F to 221 °F)
Temperature: 2 °C to 45 °C (35.0 °F to 113°F)
Pressure: <400 kPa (60 psi, 4 bar)
Drain: Atmospheric
Sample Outlet ½ in barb fitting
Security 3 access-levels security; partial and /or all settings may be protected via 3
and /or 4 digit security code.
Alarms Two continuous, assignable, programmable configurable, fail safe,
NO/NC alarm relays: SPDT, Form C, rated 10 A 115 V/5 A 230 V
Outputs Two continuous, assignable, programmable 4 mA to 20 mA, or 0 mA to
20mA outputs; isolated, max. Load 600 Ω; Convertible from 1 VDC to 5
VDC or 0 VDC to 5 VDC.
Communication
Via RS485 bi-directional serial data port; require IC Net™ 2000 software.
1-800-742-1413 www.aquametrix.com
9
AQUAMETRIX INC.
Specifications
AM-A2104033 pH Sensor
Measurement Range.........................................................................................0 pH to 14 pH units
Minimum Temperature.................................................................................................0 °C (32 °F)
Maximum Temperature..........................................................................................100 °C (212 °F)
Maximum Pressure..............................................................................................689 kPa (100 psi)
Minimum Flow Velocity........................................................................................15 cm/s (0.5 ft/s)
Wetted Materials....................................................................................CPVC, PTFE, Viton, Glass
Electrode Dimensions
Diameter.....................................................................................................................2.3 cm (0.9 in)
Length.......................................................................................................................16.5 cm (6.5 in)
Process Connection..............................................................fixed in the flow cell via a 1 in MNPT
CPVC quick connect insertion fitting
Sensor Cable.........................................................................................2 conductor; 1.5 m (5 ft) in
length with BNC connector
Preamplifier.........................................................................................................................Remote
Weight.........................................................................................................................0.5 kg (1.1 lb)
Shipping Weight........................................................................................................0.9 kg (2.0 lb)
Shipping Dimensions.................................................................................30 cm × 23 cm × 23 cm
(12 in × 9 in × 9 in)
1-800-742-1413 www.aquametrix.com
10
AQUAMETRIX INC.
Specifications
AM-A2104034 Chlorine Sensor
Measurement Range
Free Available Chlorine (HOCl)....................................................................0.00 mg/L to 2.00 mg/L
Total Free Available Chlorine (HOCl + OCl⎯)................................................0.00 mg/L to 5.00 mg/L
Minimum Temperature.................................................................................................0 °C (32 °F)
Maximum Temperature............................................................................................80 °C (176 °F)
Maximum Pressure..............................................................................................621 kPa (90 psi)
Principle of Operation.......................................................................................................Galvanic
Electrode Materials
Cathode......................................................................................................................................Gold
Anode.......................................................................................................................................Silver
Minimum Flow Velocity........................................................................................15 cm/s (0.5 ft/s)
Wetted Materials..............................................................................................CPVC, PTFE, Viton
Electrode Dimensions
Diameter.....................................................................................................................2.3 cm (0.9 in)
Length.......................................................................................................................16.5 cm (6.5 in)
Process Connection..............................................................fixed in the flow cell via a 1 in MNPT
CPVC quick connect insertion fitting
Sensor Cable...............................................................................4 conductor; 1.5 m (5 ft) in length
with 5-pin DIN connector
Weight.........................................................................................................................0.5 kg (1.1 lb)
Shipping Weight........................................................................................................0.9 kg (2.0 lb)
Shipping Dimensions.................................................................................30 cm × 23 cm × 23 cm
(12 in × 9 in × 9 in)
1-800-742-1413 www.aquametrix.com 11
AQUAMETRIX INC.
I
INSTALLATION
Analyzer Mounting
The model 8760CLP comes as a complete sample conditioning system. The analyzer is mounted on a
CPVC panel with a dual flow cell containing the pH and chlorine sensors. The sample conditioning
system includes a pressure regulator valve, sample point and atmospheric drain. The only installation
requirement of the user is to mount the panel and supply plumbing to the inlet and from the outlet.
The panel mounts on a wall via four ⅜ inch bolts at 12¼ inch x 24¼-inch centers; refer to drawing
D4040081 for mounting dimensions. Sample inlet and outlet plumbing hookup is via a ½ in barb fitting.
Analyzer Wiring
8760CLP Component
Identification
A) Identification label; indicates complete model
number and serial number
llustration 7: 8760CLP component identification
B) Analyzer, model 8760CL
C) pH sensor, P/N AM-A2104033
D) Chlorine sensor, P/N AM-A2104034
E) Atmospheric drain
F) Flow cell; a cleaning injection port is located
on the underside of the chlorine sensor flow cell
housing (hidden from view by the pressure
gauge)
G) Pressure gauge
H) Pressure regulator
I) Flow control/shut-off valve
J) Inlet
K) Outlet
1-800-742-1413 www.aquametrix.com
12
AQUAMETRIX INC.
ANALYZER WIRING
Please refer to drawing D5040276 and perform the following:
1. The 8760CLP requires 115 VAC or 230 VAC power to be hooked up to TB400. Power consumed is
less than 1 A so generally 16 gauge wire is OK (consult local electrical codes for verification). For
stable operation, the microprocessor needs a good earth ground.
CAUTION: Confirm that the 115/230 VAC switch is correctly set for your feed.
2. If required, connect the two relay contacts; as supplied, they are not powered. They are typically
used as L1 (HOT) circuit ON-OFF switches, in NO (normally open) configuration to control the
chlorine or acid (pump/valve). Best practice uses a separate circuit to isolate the sensitive sensing
circuits from any pump or solenoid inductive surges however, as a convenience for light loads, a 3 A
circuit fuse can be installed at F402 to feed the 8760CL L1 HOT to COM on relay A.
Alarm A contact TB300, closest to AC lines.
Alarm B contact TB301.
3. If required, connect the two-isolated 4 mA to 20 mA outputs, these are 24 VDC.
Output 1, TB303, closest to the relays.
Output 2, TB304.
4. Connect the inputs.
Chlorine sensor is direct connected to the analyzer via a 5-pin DIN connector.
pH sensor is direct connected to the analyzer via a BNC connector.
Sensor Mounting
Optimum sensor performance with minimum user effort is provided through the use of the factory
integrated sample system; 35.5 cm x 66.0 cm (14 in x 26 in) CPVC sample panel with pressure
regulating valve, flow setting valve, atmospheric break, grab sample point, drain, plus dual flow cell
housing the chlorine and pH sensors. The chlorine sensor and pH sensor are fixed in the flow cell via a
1 in MNPT CPVC quick connect insertion fitting.
The sensors are mounted within the sensor lead length, as near as possible to the chlorine analyzer. The
flow cell is arranged so that the sensors are mounted on a 45-degree rising line, with the sensor's tip
down at an angle anywhere from 15 degrees above horizontal to 15 degrees vertical. 45 degrees above
horizontal is best because air bubbles will rise to the top and grit will sink, both bypassing the sensor.
The pressure-regulating valve installed before the flow cell functions to control and stabilize flow. The
atmospheric drain allows for the collection of representative samples without disturbing sample
conditions and acts as a vent for bubbles. The drain line should be larger than the sample line to allow
for purging of sediments, bubbles, biologicals and other debris.
Sensor Wiring
The basic wiring scheme for AquaMetrix chlorine sensor and pH sensor is shown in drawing D5040276.
This wiring scheme is intended for cable lengths less than 20 meters (65 feet) where electrical
interference is low. The chlorine sensor has a 5-pin DIN connector and the pH sensor has a BNC
connector. This allows the sensors to be connected and disconnected easily at the analyzer.
Take care to route all signal wiring away from AC power lines, to minimize unwanted electrical
interference. Avoid twisting the sensor lead, to minimize possibilities for broken wire. Make sure that
the sensor connections are clean and tight.
1-800-742-1413 www.aquametrix.com
13
AQUAMETRIX INC.
I
k
Instrument Shop Test Startup
1. Apply 115/230 VAC power to the analyzer.
2. Hook up the chlorine sensor to bottom of analyzer via 5-pin DIN connector. Ensure that the shorting strap on
the sensor connector is removed (refer to illustration 8). Keep shorting jack for future use.
3. With the chlorine sensor in air, the 8760CL analyzer should come up reading 0.0 ppm ± 0.05 ppm.
4. Run an “air” zero check; use wires to be field installed and allow 30 minutes warm-up time for the electronics
to stabilize.
5. Run a “span” check. In the [tFCl] menu, change to these settings: [tc] [SEt] [25.0] and [pH.C] [SEt] [7.50].
A fairly accurate 1 ppm chlorine standard can be made from commercially available bleach; use a fresh 5.25%
solution.
a. Pipet 0.1 mL of bleach into a 1.0 L volumetric flask.
b. Fill to mark with deionized water. This will produce a 5 ppm standardizing solution.
c. Pipet 20 mL of the 5 ppm solution into a 100 mL volumetric flask.
d. Fill to mark with deionized water. This solution should be used immediately after prepared
and then discarded after 2 hours.
e. Fill a plastic beaker with the 1-ppm chlorine standard and place the chlorine sensor into the
beaker and stir.
f. Wait 10 minutes; the 8760CL should read 1.0-ppm ± 0.3 ppm.
Return the [tc] and [pH.C] settings back to [Auto].
6. To check for general performance, place the chlorine sensor in running tap water (chlorinated tap water should
be between 0.2 ppm and 1.0 ppm). The display should read in that range.
7. Hook up the pH sensor via the BNC connector on the underside of the 8760CL analyzer and remove orange
protective cap from sensor tip. Keep the cap for future use.
8. With the pH sensor in pH 7 buffer, the pH analyzer should display a reading of 7.0 ± 0.5 pH.
9. Run a “zero” calibration; 7 pH is equivalent to 0.0 mV so use pH 7 buffer.
10. Run a “span” calibration by placing the sensor in pH 4 buffer. The display should read approximately
4.01 ± 0.05 pH.
11. To check for general performance, place the pH sensor in pH 7 buffer again. It should now read approximately
7.0 ± 0.05 pH.
12. The sensor is now ready for field installation.
13. If the application will be in the caustic region, repeat steps 10 & 11 using pH 10 buffers so that the sensor is
tested in the region of use.
14. Before placing the 8760CL analyzer into operation, verify
the settings to ensure that they agree with the intended
setup. Factory defaults are listed in Appendix B. For the 4
mA to 20 mA output, set high limit and low limit.
Set preference for temperature units, ° C or ° F in [CONF]
15.
[unit]; default is ° C.
16. Set desired input signal damping, if known; default is
5 seconds.
17. The analyzer is now ready for field installation.
llustration 8: Pin location for chlorine sensor shorting jac
1-800-742-1413 www.aquametrix.com
14
AQUAMETRIX INC.
STARTUP
If the analyzer is new and has not been installed, follow the procedures described in Installation and
Configuration of Program before mounting. Mounting and wiring procedures for new installations vary
with equipment options — see drawing section for instructions. If the analyzer has been previously
installed, all that is required is to attach the electrode to the analyzer and then to turn on the power.
The analyzer will go through its automatic startup procedure any time power to the analyzer was lost for
more than a few seconds. The startup procedure initializes the analyzer program, performs error
checking, and then proceeds to display the chlorine and operate the analyzer normally.
All program settings, calibration settings, and the analyzer will have remembered defaults, as the
memory is none volatile.
Analyzer Startup Tests
The startup procedure will begin by alternately flashing [tESt] and [——] and blinking the top LED
while performing the memory tests. The analyzer will then display in sequence the analyzer number, in
this case [8760CL], any software option numbers, and the program version number, eg.[2.10]. The
program then proceeds to the display test that will light each of the implemented display segments in
turn. At the same time each of the LEDs will be lighted. If the analyzer passes all the tests, then the
hardware is functioning properly and the analyzer will proceed to display total free chlorine.
If the analyzer displays +Err or -Err, this indicates that the input is off-scale. The error LED will be
lighted as long as any input is off-scale. An off-scale error can indicate that the electrode is not in
solution, is off-scale, or is not connected properly. If the error LED remains lighted, go to the error
display section (select [Err] from main menu) to see what errors the analyzer has detected.
Calibration Settings Retained
If the analyzer was calibrated previously then the analyzer will use the calibration settings from the last
successful calibration, otherwise default settings are used. Error and caution messages generated during
the last calibration will remain in effect. AquaMetrix recommends a full chemical calibration of
chlorine after initial startup. Refer to the Chlorine Calibration section.
Analyzer settings and parameters can be viewed and/or changed at any time. Refer to the menus on
pages 3 to 5; the areas shaded in dark gray indicate program settings.
1-800-742-1413 www.aquametrix.com
15
AQUAMETRIX INC.
I
Easy to use Menu
The layout of the program is shown in the menus starting on page 3.
Remembers Where You Were
The analyzer remembers where SAMPLE is. The sample display is
home base for the program. The program also remembers which menu
selections were used last and loops around the columns. The menu can
be accessed using the arrow keys to find any parameter then press
SAMPLE to return to the displayed reading. Then, using the Right
arrow key return to exactly where you were.
Home Base: Press Sample
From anywhere in the menu, the SAMPLE key can be used to return to
displaying tFCl. The program will safely abort whatever it was doing at
the time and return to displaying the tFCl reading.
The tFCl display is the default sample display for the analyzer. The
analyzer's inputs, tFCl, HOCl, pH and temperature, are arranged
underneath each other at the left-hand side of the menu. Use the Up or
Down arrow key to display each of the readings in turn.
Display Features
1. The analyzer has a built-in timer, which returns the program to
displaying tFCl if no key is pressed for 15 minutes. This time-out has
the same effect as pressing the SAMPLE key. If security has been
enabled, then the time-out will change the access level back to 0 or 1
automatically, which gives the user read-only access. The user will
have to enter an appropriate password to go to a higher access level.
2. When the sample value is displayed, pressing the Left arrow key will
show which of tFCL, HOCl, pH or temperature is displayed. Pressing
Right arrow key displays the sample reading again.
3. The main sample, i.e. the input that is displayed first when the SAMPLE
key is pressed, can be changed. By default the main input is [tFCl].
Change the default in [CONF] [in] [dFLt]. Refer to the Configuration
of Program section for further details.
llustration 10: Main menu
Illustration 9: Home base
1-800-742-1413 www.aquametrix.com
16
AQUAMETRIX INC.
I
d
Arrow Keys
The four arrow keys on the keypad are used to move around in the menu.
Example:
Press SAMPLE to make sure that display is at home
base. Press the Right arrow key. One of the prompts
in the column starting with [out] will be displayed.
Use the Up or Down arrow keys to display the prompt
above or below. If the prompt at the top or the bottom
is displayed, the program will loop around. Press the
Up or Down key until [AL] is displayed. Press the
Left key to return to the sample display. Press the
Right key again and [AL] will be displayed.
llustration11: Analyzer keypa
AUTO and MANUAL Keys
The AUTO and MANUAL keys are used to implement the alarm override feature. Refer to the heading
Manual Alarm Override in the Alarm Functions section.
Standby Mode
Standby mode can be selected from the main menu. In standby mode the alarms will not function and
the 4 mA to 20 mA outputs will go to 4.00 mA. When SAMPLE is pressed, all the inputs will show
[StbY] instead of the normal input measurement.
The analyzer will not resume normal operation until the analyzer is
taken out of standby mode. While in standby mode, the entire
menu and all of the settings are accessible to the operator as before.
None of the settings will take effect until the analyzer is returned to
normal operation.
The standby feature is protected by security level 2.
Illustration 12: Standby menu
Output Hold
The 8760CLP features an automatic output hold for the pH input only. Output hold goes into effect as
soon as SELECT is pressed when [CAL] is displayed. The output hold feature avoids false alarms and
erratic signal output that would be caused by a routine calibration. Output hold is not necessary for the
chlorine input as chlorine calibration is performed by grab sample calibration only.
Output hold for the pH input has the following effect:
• 4 mA to 20 mA output signal for pH is frozen at it's current level
• Alarms for pH are temporarily disabled
If the output signal for pH is not acceptable at the value found, it can be changed for the duration of the
calibration. Select [Hold] from the pH menu to display the pH value used by the analyzer to determine
the output signal. Use the normal editing procedure to change the pH value used for output hold.
The output hold remains in effect for the duration of the calibration, that is, the output hold is disabled
when the [CAL] prompt is displayed, the SAMPLE key is pressed, or after no key has been pressed for
15 minutes.
1-800-742-1413 www.aquametrix.com
17
AQUAMETRIX INC.
Edit Mode
Edit mode is used to change a numeric value or to select between different options. Values and settings
that can be edited are identified by the darker shading in the menu. Any frame, which has a white
background, cannot be modified.
Editing by Selecting a Setting
Editing a value is like picking an option from a list; only one item on the list can be seen at a time. To
change the setting, press ENTER to go into edit mode. The display will start blinking. Use the Up or
Down arrow key to switch between the possible options and then press ENTER again to accept the new
setting and leave edit mode.
Example: Turn alarm A off.
From the menu, select [AL] [AL.A] [ON.OF]. The analyzer will now display either [ON] or [OFF],
which are the two choices. To change the setting, press ENTER to go into edit mode. The display will
start blinking. Use the Up or Down arrow key to switch between the possible options. When [ON] is
displayed, press ENTER again to accept the new setting and leave edit mode.
Summary of Key Functions in Edit Mode
Enters edit mode. The entire display or a single digit will blink to indicate that the
analyzer is in edit mode. Press the ENTER key again to leave edit mode and accept the
new value.
Adjusts blinking digit upward or selects the previous item from the list. If a 9 is displayed
then the digit will loop around to show 0.
Adjusts blinking digit downward or selects the next item from the list. If a 0 is displayed
then the digit will loop around to show 9.
Numeric values only: move to the right one digit. If blinking is already at last digit, the
display will loop to the ± sign on the left.
Numeric values: move left one digit. If blinking is at the ± sign then blinking goes to last
character.
Settings: restore the initial value if it was changed. Otherwise leaves edit mode without
doing anything.
Illustration 13: Edit keys
1-800-742-1413 www.aquametrix.com
18
AQUAMETRIX INC.
Temperature °C or °F
By default, the analyzer will use metric units. This means that temperature will be displayed using
degrees Celsius and that the prompt for the temperature input will be [°C]. The analyzer can also use
imperial units. For imperial units, temperature will be displayed using degrees Fahrenheit and the
prompt for the first temperature input will be [°F] instead of [°C].
In this instruction manual, the temperature input is always identified as [°C] throughout the menus.
To select imperial units for the analyzer, select [unit] from the configuration menu, then go into edit
mode and change the [°C] setting to [°F].
Real-Time Clock
The analyzer clock is used for internal date/time stamping of system events and the internal data log.
Both the system events and the internal data log are accessed using the IC Net Intelligent Access
Program, which is available as option -2. Analyzers purchased with option -B have a real-time clock
which will maintain the correct time and date even when the analyzer power is turned off.
Input Damping
The chlorine, pH and temperature measurements can be damped to provide the user with a means to
stabilize rapidly varying or noisy signals. Damping range is 3 s to 99 s. With 0 seconds, there would be
no damping and each reading the analyzer made would be used to directly update the display and 4 mA
to 20 mA output. The factory default of 5 seconds adds the next four seconds of readings to the first and
divides by five ― this gives fast response. Selecting 99 seconds adds the readings for 99 seconds and
divides by 99, providing smooth damping out of turbulent readings. Any selection between 3 s and 99 s
can be made.
Select [CONF] [in] from the menu. Use the Up or down arrow key to select the input to be adjusted,
then select the [dA] frame. Press ENTER, then change the input damping to the new number of seconds.
Press ENTER again to leave edit mode.
1-800-742-1413 www.aquametrix.com
19
AQUAMETRIX INC.
H
q
q
q
q
q
q
q
q
q
I
APPLICATION INFORMATION
Chlorine Chemistry
When chlorine gas is dissolved in water, it hydrolyzes rapidly according to equation 1. This reaction
occurs very rapidly, in only a few tenths of a second at 18 °C.
1)
Cl
2 g
2Oaq
— HOC
l aq
HCl
aq
Since HCl (hydrochloric acid) is a strong acid, the addition of gaseous chlorine to water results in a
lowering of the pH due to the acidic HCl by-product.
The important product of reaction (1) is HOCl or hypochlorous acid. Hypochlorous acid is the
disinfectant form of chlorine in water. Hypochlorous acid is unstable because the chlorine molecule is
weakly bonded and as a result will react quickly.
Hypochlorous acid is also referred to as free available chlorine, or free chlorine. It is taste free and
aggressive against germs and organic compounds.
Chlorine supplied as sodium hypochlorite, calcium hypochlorite, or bleach is in a basic form. When a
base is present, a different reaction sequence occurs:
2)
3)
In any hypochlorite solution, the active ingredient is always hypochlorous acid. Then once HOCl and
OH
4)
NaOCl
Ca OCl
-
are formed an additional reaction occurs:
HOCl
H2O
a
2 a
OH
a
a
2 H2O
1
— OCl
— HOCl
— 2 HOCl
a
1
Na1OH
a
H2O
Ca22 OH
a
a
1
1
The proportion of chlorine, hypochlorous acid, and hypochlorite ion in solution depends primarily on
pH and somewhat on temperature. The different forms of chlorine are named as follows:
Cl2chlorine
HOCl hypochlorousacid
OCl1hypochlorite ion
At atmospheric pressure and 20 °C, the maximum solubility of chlorine is about 7,395 mg per liter or
7.395 ppm.
Chlorine and the effect of pH
The most important reaction in the chlorination of an
aqueous solution is the formation of hypochlorous acid.
The hypochlorous acid form of chlorine is very
effective for killing germs. Hypochlorous acid is a
‘weak’ acid, meaning that it tends to undergo partial
dissociation to form a hydrogen ion and a hypochlorite
ion. Once in a water environment, HOCl tends to
dissociate into H
5)
HOCl
1-800-742-1413 www.aquametrix.com
+
and OCl- ions.
— H
a
1
OCl
1
llustration 14: Chlorine species change vs. pH
20
AQUAMETRIX INC.
I
In waters between 5 pH and 8.5 pH, the reaction is incomplete and both species are present to some
degree. Since H
+
is one of the ions that is formed and it's concentration is expressed as pH, it follows
that changing pH levels will influence the balance of this reaction and with it the availability of
hypochlorous acid for reaction.
In a water environment, the water pH will affect the chemistry of chlorine due to it's pH sensitivity.
This becomes important as pH rises.
1
6)
H2O —H1OH
(preference is right-to-left)
Three things follow from this form of ionization:
1. Since the tendency of these two ions to react and form
2O is much stronger than the tendency of water to
H
break down into the ions, it follows that as the pH rises
there are fewer H
+
2. The H
released by the breakdown of HOCl (equation
5) react to form water (equation 6) and leave behind
residual OCl
+
ions and more OH- ions.
-
(hypochlorite) ions. Hypochlorite does
not react readily, so the chlorine is weaker.
+
3. If the pH goes down and H
available again, the OCl
-
ions revert to HOCl, which is
ions become readily
the killing form of chlorine. This pH change has been
known to cause surprise downstream fish kills.
Terminology
In the industry, there are a number of terms used to
indicate the various forms of chlorine that are of interest. These terms tend to be used rather loosely and
not necessarily consistently. For that reason, AquaMetrix will define the following terms for purposes
of this instruction manual and the 8760CLP system:
llustration 15: Chlorine concentration vs. pH
FREE AVAILABLE CHLORINE refers to the hypochlorous acid (HOCl) form of chlorine only. It is
said to be free available because it is the free, uncombined form of chlorine that is effective for killing.
TOTAL FREE CHLORINE refers to the sum of hypochlorous acid (HOCl) and hypochlorite ion
-
). The hypochlorite ion is not effective for killing, but it is in a free form. All of the total free
(OCl
chlorine would be in the form of hypochlorous acid if the pH is low enough.
COMBINED CHLORINE refers to chlorine which is not readily available, is not an effective
disinfectant and will not readily convert to hypochlorous acid or hypochlorite ion. For example,
chlorine combined as chloramines or organic nitrogen.
TOTAL RESIDUAL CHLORINE refers to the sum of total free chlorine and combined chlorine. In
environmental studies low total residual chlorine is of particular interest to ensure no downstream
consequences for aquatic life. Total residual chlorine is commonly monitored for final effluent.
1-800-742-1413 www.aquametrix.com
21
AQUAMETRIX INC.
Disinfectant Properties of Chlorine
Chlorine is known to be a good disinfectant; it is able to kill living matter in water such as bacteria,
cysts, and spores. Exactly how chlorine works to kill is not known. Studies do agree, however, that
certain forms of chlorine are more effective disinfectants than others. Whatever the chemical reaction, it
is also generally agreed that the relative efficiency of various disinfecting compounds is a function of
the rate of diffusion of the active agent through the cell wall. Factors which affect the efficiency of
destruction are:
• Nature of disinfectant (type of chlorine residual fraction)
• Concentration of disinfectant
• Length of contact time with disinfectant
• Temperature
• Type and concentration of organisms
• pH
HOCl is the most effective disinfectant of all the chlorine forms and is similar in structure to water. The
germicidal efficiency of HOCl is due to the relative ease with which it can penetrate cell walls. This
penetration is comparable to that of water, and can be attributed to both it's modest size and to it's
electrical neutrality.
The concentration of hypochlorous acid is dependent on the pH, which establishes the amount of
dissociation of HOCl to H
+
and OCl
-
ions. Lowering the temperature of the reacting solution suppresses
the dissociation; conversely raising the temperature increases the amount of dissociation.
-
The rate of dissociation of HOCl is so rapid that equilibrium between HOCl and the OCl
ion is
maintained, even though the HOCl is being continuously used up.
-
The hypochlorite ion (OCl
) form of chlorine is a relatively poor disinfectant because of it's inability to
diffuse through the cell wall of microorganisms. The obstacle is the negative electrical charge.
1-800-742-1413 www.aquametrix.com
22
Loading...