Analytical Technology A15 User manual

Model A15/76
Turbidity Monitor
Home Office EuropeanOffice
Analytical Technology, Inc. ATI (UK) Limited
6 Iron Bridge Drive Bank Chambers, 33 Stamford St.
Collegeville, PA 19426 Mossley, Ashton-u-Lyne OL50LL
Ph:[phone] Ph: 0800-018-4020
[phone] + 44 (0) 1457 832800
Fax: [phone] Fax:+ 44 (0) 1457 839500
Email: [email protected]om Email:[email protected]

PRODUCT WARRANTY
Analytical Technology, Inc. (Manufacturer) warrants to the Customer that if any part(s)
of the Manufacturer's products proves to be defective in materials or workmanship within the
earlier of 18 months of the date of shipment or 12 months of the date of start-up, such
defective parts will be repaired or replaced free of charge. Inspection and repairs to products
thought to be defective within the warranty period will be completed at the Manufacturer's
facilities in Oaks, PA. Products on which warranty repairs are required shall be shipped freight
prepaid to the Manufacturer. The product(s) will be returned freight prepaid and allowed if it is
determined by the manufacturer that the part(s) failed due to defective materials or
workmanship.
This warranty does not cover consumable items, batteries, or wear items subject to
periodic replacement including lamps and fuses.
Gas sensors, except oxygen sensors, are covered by this warranty, but are subject to
inspection for evidence of extended exposure to excessive gas concentrations. Should
inspection indicate that sensors have been expended rather than failed prematurely, the
warranty shall not apply.
The Manufacturer assumes no liability for consequential damages of any kind, and the
buyer by acceptance of this equipment will assume all liability for the consequences of its use
or misuse by the Customer, his employees, or others. A defect within the meaning of this
warranty is any part of any piece of a Manufacturer's product which shall, when such part is
capable of being renewed, repaired, or replaced, operate to condemn such piece of
equipment.
This warranty is in lieu of all other warranties (including without limiting the generality of
the foregoing warranties of merchantability and fitness for a particular purpose), guarantees,
obligations or liabilities expressed or implied by the Manufacturer or its representatives and by
statute or rule of law.
This warranty is void if the Manufacturer's product(s) has been subject to misuse or
abuse, or has not been operated or stored in accordance with instructions or if the serial
number has been removed.
Analytical Technology, Inc. makes no other warranty expressed or implied except as
stated above.

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TABLE OF CONTENTS
UNPACKING.............................................................................................................................................4
INTRODUCTION.......................................................................................................................................5
FIGURE 1 -TURBIDITY SYSTEM WITH SUBMERSION SENSOR (ATI-0471)..................................5
SPECIFICATIONS....................................................................................................................................6
Electronics Unit............................................................................................................................6
Sensor..........................................................................................................................................6
INSTALLATION.........................................................................................................................................7
FIGURE 2 - PANEL MOUNT MONITOR DIMENSIONS & INSTALLATION (ATI-0124,125) .......7
FIGURE 3 - NEMA - 4X WALL MOUNT DIMENSIONS & INSTALLATION (ATI-010) ..................8
FIGURE 4 - HANDRAIL MOUNTING ASSEMBLY FOR NEMA 4X ENCLOSURE (ATI-043)..............9
FIGURE 5 FLOWCELL DIMENSIONS (ATI-0435)............................................................................10
FIGURE 6 EXPLODED FLOWCELL AND SENSOR ASSEMBLY (ATI-0470) .................................10
FIGURE 7 – FLOW TEE RECOMMENDED PIPING (ATI-0793)........................................................11
FIGURE 8 – FLOW TEE TYPICAL CONFIGURATION (ATI-0513)....................................................12
FIGURE 9 – FLOW TEE ASSEMBLY (ATI-0542)...............................................................................13
FIGURE 10 - SUBMERSIBLE SENSOR MOUNTING (ATI-0447)......................................................14
ELECTRICAL CONNECTIONS................................................................................................................15
FIGURE 11 – TURBIDITY SYSTEM CONNECTIONS (ATI-0443).....................................................15
FIGURE 12– TURBIDITY SYSTEM WITH JUNCTION BOX CONNECTIONS (ATI-0445)................16
START-UP................................................................................................................................................17
Front Panel Lock..........................................................................................................................18
CONFIGURATION....................................................................................................................................19
OPERATION.............................................................................................................................................21
Setting Zero..................................................................................................................................21
Setting Sensitivity (Span).............................................................................................................22
CONTROL & ALARM OUTPUTS .............................................................................................................23
Control Relays..............................................................................................................................23
Alarm Relay..................................................................................................................................24
Auto/Manual Operating Mode......................................................................................................24
Check Signal Display...................................................................................................................25
MAINTENANCE........................................................................................................................................26
Sensor Maintenance....................................................................................................................26
SPARE PARTS LIST - MODEL A15/76....................................................................................................27

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UNPACKING
When you receive your Turbidity Monitor, open the shipping package and inspect the contents to be sure
that all items have been received. The items shipped will depend on the type of system ordered. The following is
a list of items normally supplied with standard flow type systems.
Quantity 1 - Model A15/76 Turbidity Monitor Electronics, NEMA 4X (if ordered)
Quantity 1 - Turbidity Sensor
Quantity 1 - Flowcell Assembly with mounting bracket
Quantity 1 - Sensor cable assembly, 30 feet
Quantity 1 - Operation & Maintenance Manual
If you ordered a system with a submersible sensor, your package will not contain a flowcell assembly.
Instead, you will receive a two-part submersion sensor holder.
In addition to the standard items listed above, any additional spare parts or spare sensors that were
ordered separately will be included. Compare the contents of the shipping container with the packing list. The
items listed above are the standard components that are included with every standard A15/76 Turbidity monitor.
Any other items will be listed separately on the packing list. Check the contents of the shipping container
carefully to insure that nothing is overlooked. Should you find anything missing from the shipment, immediately
contact the ATI sales department by calling either 800-959-0299 or 610-917-0991. If you prefer, you may send a
fax describing the error to 610-917-0992.

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INTRODUCTION
The Model A15/76 is an on-line monitoring system designed for the continuous measurement of the
turbidity of an aqueous stream. It is primarily intended for monitoring turbidity in drinking water or wastewater
effluent. The monitor provides display ranges from 0-4.000 NTU up to 0-4000 NTU. The display range used for a
given application is user programmable, and an auto-ranging feature allows the display of high turbidity values,
even when programmed for low range use. A15/76 monitors are designed to operate on samples at
temperatures from 0°to 50 °C and pressures of 0-100 PSIG. The measured turbidity is displayed on a backlit
liquid crystal display on the front of the instrument.
The sensor used in the A15/76 system measures turbidity using a 90-degree light scattering technique.
An infrared LED light source emanates from a planer surface and a detector in the same plane measures light
scattered at 90 degrees to the incident light beam. An automatic zero correction system allows measurement of
very low turbidity values with excellent zero stability. The sealed flowcell used for low level measurements is
designed to allow measurement of a pressurized sample in order to avoid errors caused by bubbles formed when
sample pressures are reduced.
For wastewater application, or where a submersible measurement is desired, the turbidity sensor is
supplied with a special holder to minimize ambient light effects. The submersible assembly eliminates the need
for sample pumps, and will operate at turbidity values up to 4000 NTU. For applications where fouling is a
problem, a special “Auto-Clean” version of the turbidity sensor is available. Contact your ATI representative for
details.
FIGURE 1 -TURBIDITY SYSTEM WITH SUBMERSION SENSOR (ATI-0471)

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SPECIFICATIONS
Electronics Unit
Range: 4/400 NTU (0-4.000, 0-40.00, 0-400.0)
40/4000 NTU (0-40.00, 0-400.0, 0-4000)
9/999 mg/l (or PPM) SiO2(0-9.999, 0-99.99, 0-999.9)
99/9999 mg/l (or PPM) SiO2 (0-99.99, 0-999.9, 0-9999)
Auto-ranging over 3 decades of concentration
Sensor Type: 90°Scatter (nephelometer)
Accuracy: ± 5% of reading or ± 0.02 NTU, whichever is greater, on 40/400 scale
± 10% of reading or ±2 NTU, whichever is greater, on 400/4000 scale
Linearity: 0.1% of F.S.
Display: 16 character alphanumeric backlit LCD
Control Relays: Two SPDT relays, 5A @ 220 VAC resistive.
Programmable deadband and time delay.
Control Mode: On/Off
Alarm Relay: Independent SPDT relay, 5A @ 220 VAC resistive.
Programmable for actuation on high/low values or control system failure.
Also indicates dry cell condition, fouled sensor, or high ambient light
Analog Output: Isolated 4-20 mA, 600 ohm maximum load. Programmable output range user set
Operating Conditions: -20° to +55° C., 0-95% R.H. non-condensing.
Power: 110/220 VAC ±10%, 50/60 Hz.
Enclosure: Panel mount standard
NEMA 4X wall mount optional
Sensor
Range: 0-4000 NTU
Measurement angle: 90-degree scatter (nephelometric)
Response Time: 95% in 10 seconds
Power: ±12 VDC supplied by monitor, preamplifier in sensor head
Temperature Limits: 0 - 50° C.
Pressure Limits: 0 - 100 PSIG
Connections: 7-conductor sensor cable to monitor, 30 feet standard, 350 feet maximum
Sensor Materials: Delrin body, Acrylic optical windows
Flowcell Materials: PVC
Flowcell Connections: 4 mm tube fittings (black tubing supplied)
Flowcell Pressure: 0-100 PSIG
Flowcell Temperature: 0-60° C

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INSTALLATION
The main installation requirements for ATI’s Turbidity Monitor are mechanical installation, and connection
of power to the monitor. Figure 1 on page 5 shows a schematic of a typical installation of a complete system.
The monitor should be located near the sensor in order to use the standard 30 foot sensor cable supplied with the
system. Longer cable runs can be accommodated using a junction box and additional 7-conductor cable.
Figure 2 provides details on the mechanical installation of the standard panel mount electronic assembly.
The panel cutout must be made accurately as the cutout tolerance is small. Panel mounting brackets are
included with the monitor and are attached as shown below.
6
.
10
"
155mm
5.46"
139mm
.34"
8.6mm
3.54"
90mm
3.78"
96mm
SIDE VIEWFRONT VIEW
3.78"
96mm
MOUNTING BRACKETS
(TYPICAL 2 PLACES)
MOUNTING BRACKET INSTALLATIONPANEL CUTOUT
3.60"
91.4mm
3.60"
91.4mm
FIGURE 2 - PANEL MOUNT MONITOR DIMENSIONS & INSTALLATION (ATI-0124,125)

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The optional NEMA 4X wall mount enclosure is a Molded Plastic ABS unit that bolts directly to a wall or
other flat surface. The enclosure is supplied with special mounting bracket for convenience in mounting the
enclosure. A hinged door on the front of the enclosure provides access to operating controls, and a hinge on the
back section for convenience in wiring the unit.
FIGURE 3 - NEMA - 4X WALL MOUNT DIMENSIONS & INSTALLATION (ATI-010)

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A special handrail mounting kit (part # 00-0930) is available from ATI for use on standard handrails found
around many process tanks. The mounting kit consists of two vertical aluminum supports, which are clamped to
the handrail with stainless steel u-bolts. The vertical supports are drilled for connection to horizontal handrails
with 18" center to center dimensions. If other center dimensions are encountered, new holes for the upper u-bolt
will need to be drilled. Holes at the top of the vertical supports align with the mounting feet provided on the NEMA
4X enclosure. Figure 4 shows a completely assembled handrail bracket assembly. The bracket kit includes all
necessary hardware.
FIGURE 4 - HANDRAIL MOUNTING ASSEMBLY FOR NEMA 4X ENCLOSURE (ATI-043)

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The majority of turbidity applications require the use of a flowcell assembly. This method is best when
monitoring very low turbidity values, such as filter effluent. The flowcell used with ATI’s turbidity system is
designed to eliminate ambient light effects, and to allow sample pressure to be maintained through the flowcell
minimizing air bubble formation that can cause erroneous turbidity measurements. A bracket is supplied for
mounting the flowcell to any flat surface. Figure 5 and 6 show details of the flowcell mounting. The sample outlet
must be above the sample inlet for proper operation.
FIGURE 5 FLOWCELL DIMENSIONS (ATI-0435)
FIGURE 6 EXPLODED FLOWCELL AND SENSOR ASSEMBLY (ATI-0470)

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Figure 7 below shows the recommended installation tubing arrangement for the turbidity system. A 3-
way valve is supplied to facilitate calibration of the turbidity monitor. Install the valve as shown below so that
turbidity standards can easily be introduced into the flowcell.
FIGURE 7 – FLOW TEE RECOMMENDED PIPING (ATI-0793)

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Turbidity sensors may also be installed directly into a flowing pipe system provided that the water does
not contain a lot of entrained air. It is best to install the sensor in a vertical pipe section with water flowing
upward. This assures that air pockets cannot develop at the sensor. If installed in a horizontal run of pipe, place
the sensor at the 3 or 9 o’clock position. Never mount the sensor on the top or bottom of the pipe. It is also good
practice to install a bypass system around the sensor for maintenance and calibration purposes. Figures 8 and 9
show a typical installation and assembly.
FIGURE 8 – FLOW TEE TYPICAL CONFIGURATION (ATI-0513)

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FIGURE 9 – FLOW TEE ASSEMBLY (ATI-0542)

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For applications where a submersible turbidity sensor is to be used, a special submersion holder is
supplied. This holder is designed to mount on the end of a 1” mounting pipe, with the sensor cable coming up
through the center of the pipe. Figure 10 below shows a typical submersion mounting system, including both the
submersion holder assembly and ATI’s handrail mounting assembly (part number 00-0628).
FIGURE 10 - SUBMERSIBLE SENSOR MOUNTING (ATI-0447)

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ELECTRICAL CONNECTIONS
Wiring connections to the A15/73 are made to the back of the monitor. The terminal blocks on the back
of the monitor are pluggable terminals for ease of wiring. Power and alarm relay connections are made to the
lower terminal block while sensor and analog output connections are made to the upper block. Refer to Figure 11
below for a detail of the terminal connections on the rear of the turbidity monitor.
FIGURE 11 – TURBIDITY SYSTEM CONNECTIONS (ATI-0443)

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FIGURE 12– TURBIDITY SYSTEM WITH JUNCTION BOX CONNECTIONS (ATI-0445)

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START-UP
Prior to operation, recheck electrical connections to be sure everything is in accordance with Figure 11 or
11 in the previous section. If everything is in order, power may be applied. When power is turned on, the display
will come up with a program and version number, which will remain on the display for a few seconds. The display
will then change to a display of the pH value and an indication of the status of control relays. This is the main
operating display, and should look like the display below:
D1 XXXX NTU A BMAIN DISPLAY
The XXXX portion will be numbers and there will be a decimal point in a location determined by the range
of operation. The initial values could be almost anything, depending on whether the sensor has been connected
and what the condition of the sensor is. The values are not important at this point. The next portion of the display
indicates control relay status. The letters A and B refer to control relays A and B as marked on the back of the
monitor. An open square () indicates a deactivated relay while a solid square () indicates an activated relay.
More information on the control relays is provided in a later section of this manual.
Beyond the main display, a series of alternate displays are available to the operator. These displays may
be selected by pressing the MODE key on the front panel. It is a good idea to step through the displays to
become familiar with each one. Many of these alternate displays serve as a starting point for programming
functions described later in this manual. The alternate display sequence is as follows:
D2 XXXX NTU TURBIDITY DISPLAY WITHOUT ALARMS
D3 CHECK S.: XX.X% CHECK SENSOR SIGNAL INDICATOR
D4 SA XXXX NTU LRELAY A SETPOINT AND FUNCTION
D5 SB XXXX NTU HRELAY B SETPOINT AND FUNCTION
D6 AL XXXX/XXXX NTU ALARM RELAY SETPOINTS
D7 CLEANING OFF SENSOR CLEANING STATUS
D8 01: XX.X mA / XXX ANALOG OUTPUT INDICATION
D9 CONFIGURATION ACCESS TO SETUP ROUTINES
D10 TU7685 R2.XX PROGRAM AND RELEASE NUMBER

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Front Panel Lock
The key switches on the front panel of the monitor can be used for both changing the display and for
calibrations and setpoint adjustments. When the monitor is shipped from ATI, all functions are accessible.
However, the adjustment and calibration functions can be locked in order to prevent unauthorized adjustments to
the instrument. When the front panel is locked, the MODE key will still allow the display to be stepped through
the alternate displays but will not allow settings to be altered.
To lock (or unlock) the keyboard, press the MODE key until "CONFIGURATION" is displayed. Press the
CAL key once and the display will change to "KB UNLOCKED". Use the UP key to select "KB LOCKED" and
press ENTER. The UPDATE message will appear briefly and the "LCD CONTRAST" message will appear.
Press the MODE key 3 times to return to the main display.

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CONFIGURATION
The electronics for the Turbidity system are designed to be as flexible as possible. A number of
programming functions are provided in the CONFIGURATION menu and are protected by an access number,
which must be entered to allow changes in these settings. Some settings are for factory use only, while others
are used for customer selection of certain operating parameters.
Press the MODE key until the display reads CONFIGURATION and then press CAL. The display will
read "KB UNLOCKED (OR LOCKED)". Press ENTER twice and the display will read "ACCESS NR.: 0". To
gain access to the configuration routines, the access number must be entered using the UP or DOWN keys. The
default access number is 0, so you can enter the configuration menu by simply pressing ENTER. This number is
programmable and can be set to any 3 digit number desired. Remember to record any custom access number
entered into the unit in a location where you can always find it. Should you loose your access number, call ATI
for assistance with a bypass sequence.
1. Measure U.: NTU This routine allows selection of the measurement units displayed on the monitor. The
default units are NTU (nephelometric turbidity units). For special applications, the monitor can display values
in terms of milligrams per liter SiO2 or PPM. When using these alternate units, the customer must provide a
calibration media that fits the application.
2. Range: 4/400 NTU Selection of the overall operating range is done in this routine. For most low range
applications, the default values of 4/400 should be used. This allows for selection of ranges between 0-4 and
0-400 NTU. For high range applications, select 40/4000. This allows the unit to monitor in the 0-4000 NTU
range for high level applications. Select 9/999 or 99/9999 when using the mg/l or PPM ranges..
3. Scale: 4.000 NTU This routine allows selection of the actual operating range to be used. Filter effluent
applications will normally use the 0-4.000 range while raw water or filter influent monitoring will normally use
either 0-40.00 or 0-400.0 ranges
4. AUTORANGING: OFF The monitor is capable of automatically switching the display range if turbidity values
exceed the range selected in #3 above. The default is OFF. If you want to see values above the selected
range, use the UP or DOWN keys to select ON.
5. Large S RT: 40s This routine allows for electronic damping of the display and analog output signals. The
A15/76 has a two-stage filter to eliminate rapid changes in the display. This routing selects the damping used
for large changes in turbidity. The default setting is 40 seconds, which means that it takes about 40 seconds
for the display and output to reach 95% of a large step change in turbidity value. This value can be adjusted
between 5 and 220 seconds for either faster or slower response times.
6. Small S RT: 120s This routine sets the damping value for small changes in turbidity values. The value for
this damping factor is set at a fairly high value to eliminate fluctuations in the reading caused by occasional
bubbles or other sample anomalies. As with #5 above, this setting can be adjusted between 5 seconds and
220 seconds to provide the desired damping of small changes.
7. CHECK SIGNAL: ON The A15/76 contains software routines that monitor the condition of the sensor. This
“check signal” system can provide an alarm if the sensor becomes too dirty to allow accurate measurement or
if the ambient light (in a submersion application) is too high to allow for low level measurements. In addition,
the “check signal” system will warn of loss of water in the flowcell that would result in faulty readings. This
function is normally ON, but can be disabled if this feature adversely affects a particular application.

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8. CAL OUT1: 0/4-20: This routine allows output #1 to be configured as either a 0-20 mA or 4-20 mA output.
Select using the UP or DOWN keys and then press ENTER.
9. CAL P1: X.XXX NTU Analog outputs are adjusted to an overall operating range, such as 0-1.000 NTU or 0-
0.500 NTU. The CAL P1 routine allows assignment of the zero value for the output. Normally, this value will
be 0. However, you can offset the 4 mA point if desired by using the UP key. Press ENTER when the proper
value has been selected.
10. CAL P2: XX.XX NTU: The CAL P2 routine allows assignment of the full-scale value for the output. For a
turbidity output, this would be the 20 mA value for the output, such as 1.000 for a range of 0-1.000 NTU.
Press ENTER when the proper value has been selected.
11. SET A F.: LO (OR HI) This routine allows the function of setpoint A to be defined as either low or high.
When LO is selected, relay A acts like a low alarm, with the relay activating when the measured turbidity is
below the setpoint. When HI is selected, the relay acts like a high alarm, activating when the measured value
is above the setpoint. Setpoints are programmed in another routine described later in this manual.
12. SET B F.: LO (OR HI) This routine allows the function of setpoint B to be defined as either low or high
similar to relay A described in 11 above.
13. AL SET A: OFF A separate alarm relay is provided in the monitor which is independent of relays A and B. It
is marked C on the back of the instrument. This relay can be used to actuate an emergency alarm should the
turbidity value remain outside of the A setpoint for some fixed period of time. The default for this function is
off. If you want to use this function, use the UP key to select ON and then press ENTER. The display will
change to "TIME SET A: 60 M". Use the UP or DOWN key to select the time period after which you want the
C/D relay to actuate.
14. AL SET B: OFF This routine is similar to 13 above, but with respect to relay B. It associates the alarm relay
with the operation of relay B as described above.
15. EXT LIGHT AL: OFF The A15/76 turbidity monitor can detect when external light conditions are too high to
allow for accurate readings. This is especially important when measuring very low turbidity values. This
routine activates or deactivates this alarm feature. When measuring in a flowcell, external light is rarely a
problem. However, it can be a problem when measuring using a submersible sensor.
16. AL RELAY: ACT This is a factory setting and should not be changed.
17. CAL CF: DISABLED This routine is used to activate an automatic sensor cleaning system available from
ATI. The model B15/76 turbidity system incorporates an automatic air cleaning system used in submersible
applications. This function is not used in A15/76 systems as there is no source of air or timing controls
contained in this system.
18. CLEANING T: 15.0” This routine is associated with the Auto-Clean version of this product and is not used.
19. HOLDING T: 3.0’ As with 18 above, this is a routine associated with the Auto-Clean version of this product.
20. Change A Nr.: No/Yes: This routine allows you to enter your own access code number. Changing the
access number will restrict access to the configuration menu by anyone who does not know the number you
enter. To change the number, press UP to change the display to YES and press ENTER. Use the UP or
DOWN arrow to set the number you want and then press ENTER. When you press ENTER, the display will
show "Confirm Nr.: 0". To change the access number, the number must be entered twice. Use the UP or
DOWN arrows to set the same number again and then press ENTER. After the second entry, the new
number will be stored and must be used to gain access to the configuration menu from then on.