Emec MTOWER PLUS Series User manual

1
Read Carefully ! ENGLISH Version
R12-01-18
OPERATING INSTRUCTIONS F O R
“MTOWER PLUS” INSTRUMENT
This manual contains safety information that if ignored
can endanger life or result in serious injury. They are
indicated by this icon.
Keep the instrument protected from sun and water.
Avoid water splashes.
CD/PH/RH Version

2
Danger!
GENERAL SAFETY GUIDELINES
In emergencies the instrument should be switched off immediately! Disconnect the power cable
from the power supply!
When installing always observe local regulations!
Manufacturer is not liable for any unauthorized use or misuse of this product that may cause injury,
damage to persons and / or materials.
Caution! Instrument must be accessible at all times for both operating and servicing. Access must not be
obstructed in any way!
Feeder should be interlocked with a no-flow protection device to automatically shut-off the pumps
when there is no flow!
Pumps and accessories must be serviced and repaired by qualified and authorized personnel only!
Always discharge the liquid end before servicing the instrument!
Empty and rinse the liquid end before work on a pump which has been used with hazardous or
unknown chemicals!
Always read chemical safety datasheet!
Always wear protective clothing when handling hazardous or unknown chemicals!
Instrument must be operated / serviced by trained technicians only!
All connection operations must be performed while the instrument is not connected to main
supply!
NORME CE
EC RULES(STANDARD EC)
NORMAS DE LA CE
Direttiva Bassa Tensione
Low Voltage Directive
Directiva de baja tensión
Direttiva EMC Compatibilità Elettromagnetica
EMC electromagnetic compatibility directive
EMC directiva de compatibilidad electromagnética
2014/35/UE
2014/30/UE
⎬
⎬

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Introduction.
The “MTOWER PLUS” is a fully featured cooling towers controller with two-way biocide options and inhibitor / bleed
control.Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers
may either use the evaporation of water to remove process heat and cool the working uid to near the wet-bulb air
temperature or rely solely on air to cool the working uid to near the dry-bulb air temperature. Common applications
include cooling the circulating water used in oil reneries, chemical plants, power plants and building cooling.
All information is provided through a large backlit LCD display (240x64). Using a revolutionary wheel control the instrument
can be easily programmed. “MTOWER PLUS” is housed in a IP65 plastic box.
Measures are: L325 x H235 x D125 (including wheel and connectors).
Main features of “MTOWER PLUS” are:
BLEED
INHIBITOR with 5 working modes
(Feed&Bleed, Feed&Bleed Percentual , PercenutalTime, WaterMeter, WaterMeter PPM)
BIOCIDE with weekly program
Conductivity, pH and ORP Meter with Proportional and Digital outputs
The wheel.
Located in the upper right side of “MTOWER PLUS” there is a wheel used to control the instrument.
Wheel can be rotated in both directions to scroll over menus and / or pressed to conrm highlighted selection / value.
- Edit single eld submenu by pressing wheel twice.
- When in main screen keep wheel pressed to switch “OFF” instrument. Repeat procedure to switch “ON” instrument.
Rotate the wheel to cycle-loop
through all available options.
Clockwise or Counterclockwise.
Press wheel to move
on submenu for selected option.

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Mainboard Connections.
Unplug instrument from main power supply then perform connections to probes and / or selected outputs by following
the above picture. For easy understanding board has been divided into two parts: Power connections and I/O
connections.
Power Connections:
F1: General fuse (6.3AT)
F2: Circuit fuse (3.15AT)
Main power supply (from 90VAC to 265VAC):
L (live), E (earth), N(neutral)
Setpoint Outputs
(voltage output is the same as for main power supply):
1 - E - N (F1 fuse protected) D1 pH
2 - E - N (F1 fuse protected) Inhibitor
3 - E - N (F1 fuse protected) D1 mV (Biocide 1)
4 - E - N (F1 fuse protected) Biocide 2
5 - E - N (F1 fuse protected) Pre-biocide 1
6 - E - N (F1 fuse protected) Pre-biocide 2
Bleed Valve (Free Voltage Version): 7(N.C.), 8(C), 9(N.O.) Free Voltage contact
General Alarm output: 10(N.C.), 11(C), 12(N.O.) Free Voltage contact
Warning: Connections must be perfomed by qualied and trained personnel only.
L 1 2 3 4 5 6
E E E E E E E
N N N N N N N N 7 8 9 10 11 12
F1
F2
A B
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
1 2 3 4 5 6 7 8 9 1 0 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
CD Module pH
Module
]
Power Connections
]
I/O Connections
ORP
Module

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I/O Connections:
Standby / Proportional Outputs: 1: - D1 mV (Biocide1) 3: - Biocide2 5: - Pre-biocide1 7: - (Cl) 9: - pH 11: - Inhibitor
2 + D1 mV (Biocide1) 4: + Biocide2 6: + Pre-biocide1 8: + (Cl) 10: + pH 12: + Inhibitor
mA outputs (500 Ohm max resistive load): 13: Common
14: mA output 1 (conductivity)
15: mA output 2 (temperature)
16: mA output 3 (pH)
17: mA output 4 (mV)
RS485:
26: + Signal RS485 (A)
27: - Signal RS485 (B)
Tank Level inputs: 29 (-) ; 30 (+) mV Level
31 (-) ; 32 (+) Biocide 2 Level
33 (-) ; 34 (+) Pre-biocide 1 Level
35(-) ; 36(+) Pre-biocide 2 Level
37 (-) ; 38 (+) Inhibitor Level
54 (+) ; 55(-) pH Level
FLOW sensor (mod. “SEPR”) input: 39(+ Brown) ; 40(Black) ; 41(- Blue)
41 shortcut with block n.37
MANIFOLD input: 39(White) ; 40(Black)
41 shortcut with block n.37
(Hall effect) pulse sender water meter (makeup water): 42(+12VDC) ; 43(INPUT) ; 44(GND)
(Contact) Pulse sender water meter (makeup water): 43(INPUT) ; 44(GND)
(Hall effect) Pulse sender water meter (bleed water): 45(+12VDC) ; 46(INPUT) ; 47(GND)
(Contact) Pulse sender water meter (bleed water): 46(INPUT) ; 47(GND)
Temperature Probe input (mod. “ETEPT”): 50(green) ; 51(brown) ; 52(white) ; 53(yellow)
(remove resistance before to install probe)
OPTIONS
OPTIONS
OPTIONS
GND shared!
GNS shared!
(-) GND shaerd
STANDBY OUT (1-6) PROPORTIONAL OUT (7-12)

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Cooling tower basic knowledge.
What is a (wet, atmospheric) cooling tower?
A cooling tower is a heat rejection device, which extracts waste heat to the atmosphere though the cooling of a water
stream to a lower temperature. The type of heat rejection in a cooling tower is termed “evaporative” in that it allows a small
portion of the water being cooled to evaporate into a moving air stream to provide signicant cooling to the rest of that
water stream. The heat from the water stream transferred to the air stream raises the air’s temperature and its relative
humidity to 100%, and this air is discharged to the atmosphere. Evaporative heat rejection devices such as cooling towers
are commonly used to provide signicantly lower water temperatures than achievable with “air cooled” or “dry” heat rejec-
tion devices, like the radiator in a car, thereby achieving more cost-effective and energy efcient operation of systems in
need of cooling. Think of the times you’ve seen something hot be rapidly cooled by putting water on it, which evaporates,
cooling rapidly, such as an overheated car radiator. The cooling potential of a wet surface is much better than a dry one.
Common applications for cooling towers are providing cooled water for air-conditioning, manufacturing and electric power
generation. The smallest cooling towers are designed to handle water streams of only a few gallons of water per minute
supplied in small pipes like those might see in a residence, while the largest cool hundreds of thousands of gallons per
minute supplied in pipes as much as 15 feet (about 5 meters) in diameter on a large power plant.
The generic term “cooling tower” is used to describe both direct (open circuit) and indirect (closed circuit) heat rejection
equipment. While most think of a “cooling tower” as an open direct contact heat rejection device, the indirect cooling
tower, sometimes referred to as a “closed circuit cooling tower” is nonetheless also a cooling tower.
A direct, or open circuit cooling tower is an enclosed structure with internal means to distribute the warm water fed to
it over a labyrinth-like packing or “ll.” The ll provides a vastly expanded air-water interface for heating of the air and
evaporation to take place. The water is cooled as it descends through the ll by gravity while in direct contact with air that
passes over it. The cooled water is then collected in a cold water basin below the ll from which it is pumped back through
the process to absorb more heat. The heated and moisture laden air leaving the ll is discharged to the atmosphere at a
point remote enough from the air inlets to prevent its being drawn back into the cooling tower.
The ll may consist of multiple, mainly vertical, wetted surfaces upon which a thin lm of water spreads (lm ll), or several
levels of horizontal splash elements which create a cascade of many small droplets that have a large combined surface
area (splash ll).
An indirect, or closed circuit cooling tower involves no direct contact of the air and the uid, usually water or a glycol
mixture, being cooled. Unlike the open cooling tower, the indirect cooling tower has two separate uid circuits. One is
an external circuit in which water is recirculated on the outside of the second circuit, which is tube bundles (closed coils)
which are connected to the process for the hot uid being cooled and returned in a closed circuit. Air is drawn through the
recirculating water cascading over the outside of the hot tubes, providing evaporative cooling similar to an open cooling
tower. In operation the heat ows from the internal uid circuit, through the tube walls of the coils, to the external circuit
and then by heating of the air and evaporation of some of the water, to the atmosphere. Operation of the indirect cooling
towers is therefore very similar to the open cooling tower with one exception. The process uid being cooled is contained
in a “closed” circuit and is not directly exposed to the atmosphere or the recirculated external water.
In a counter-ow cooling tower air travels upward through the ll or tube bundles, opposite to the downward motion of the
water. In a cross-ow cooling tower air moves horizontally through the ll as the water moves downward.
Cooling towers are also characterized by the means by which air is moved. Mechanical-draft cooling towers rely on
power-driven fans to draw or force the air through the tower. Natural-draft cooling towers use the buoyancy of the exhaust
air rising in a tall chimney to provide the draft. A fan-assisted natural-draft cooling tower employs mechanical draft to
augment the buoyancy effect. Many early cooling towers relied only on prevailing wind to generate the draft of air.

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Cooling tower basic knowledge.
If cooled water is returned from the cooling tower to be reused, some water must be added to replace, or make-up, the
portion of the ow that evaporates. Because evaporation consists of pure water, the concentration of dissolved minerals
and other solids in circulating water will tend to increase unless some means of dissolved-solids control, such as blow-
down, is provided. Some water is also lost by droplets being carried out with the exhaust air (drift), but this is typically
reduced to a very small amount by installing bafe-like devices, called drift eliminators, to collect the droplets. The make-
up amount must equal the total of the evaporation, blow-down, drift, and other water losses such as wind blowout and
leakage, to maintain a steady water level.
Some useful terms, commonly used in the cooling tower industry:
Drift - Water droplets that are carried out of the cooling tower with the exhaust air. Drift droplets have the same concen-
tration of impurities as the water entering the tower. The drift rate is typically reduced by employing bafe-like devices,
called drift eliminators, through which the air must travel after leaving the ll and spray zones of the tower.
Blow-out - Water droplets blown out of the cooling tower by wind, generally at the air inlet openings. Water may also
be lost, in the absence of wind, through splashing or misting. Devices such as wind screens, louvers, splash deectors
and water diverters are used to limit these losses.
Plume - The stream of saturated exhaust air leaving the cooling tower. The plume is visible when water vapor it
contains condenses in contact with cooler ambient air, like the saturated air in one’s breath fogs on a cold day. Under
certain conditions, a cooling tower plume may present fogging or icing hazards to its surroundings. Note that the water
evaporated in the cooling process is “pure” water, in contrast to the very small percentage of drift droplets or water blown
out of the air inlets.
Blow-down - The portion of the circulating water ow that is removed in order to maintain the amount of dissolved
solids and other impurities at an acceptable level.
Leaching - The loss of wood preservative chemicals by the washing action of the water owing through a wood struc-
ture cooling tower.
Noise - Sound energy emitted by a cooling tower and heard (recorded) at a given distance and direction. The sound is
generated by the impact of falling water, by the movement of air by fans, the fan blades moving in the structure, and the
motors, gearboxes or drive belts.

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“MTOWER PLUS” basic treatments.
“MTOWER PLUS” basically operates three main treatments to grant cooling efciency: inhibitor, bleed and biocide.
What is the purpose of inhibitor ?
Inhibitor is a chemical compound that, when added to water, decreases the corrosion rate of a metal or an alloy. It
prevents cooling tower plant to mantain hoses efciency in water circulating system.
To set:
Working Mode
To setup and congure this function see page 22.
What does it mean bleed ?
A method for controlling the amount and concentration of make-up water and chemicals introduced into the recirculating
water of a cooling tower system. A oat operated make-up valve controls the addition of make-up water to the tower. As
make-up water is added to the tower a vacuum is produced at an injector valve which draws chemicals from a chemical
holding tank into the make-up water, thereby allowing precise control of the chemical concentration in the make-up liquid.
Further, a bleed valve is provided which is responsive to the vacuum produced at the injector valve and bleeds a portion
of the recirculating water to waste.
To set:
Setpoint
Dead band
Time Limit
To setup and congure this function see page 24.
What is a biocide ?
A biocide is a chemical substance capable of killing living organisms, usually in a selective way. They prevent the fouling
of cooling tower water. Cooling tower users frequently apply biocides to the circulating cooling water to control growth
of microorganisms, algae, and macroorganisms. Another very important reason for using biocides in cooling towers is
to prevent the growth of Legionella, including species that cause legionellosis or Legionnaires’ disease, most notably L.
pneumophila. “MTOWER PLUS” can be set to perform also a pre-biocide (biocide activator or pre biocide treatment)
activity.
To set:
Pre-bleed
Pre-biocide
Biocide
Lockout
Week
To setup and congure this function see page 23.

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“MTOWER PLUS” main screen.
Conductivity status Message Explanation Action Required
“INHIBITOR”
INHIBITOR mode in progress.
Ouput 2-E-N active
Corrosion inhibitor dosage in progress.
No action required.
“BLEED hh:mm”
BLEED hh:mm mode in progress.
Bleed Valve active
Restoring conductivity.
No action required.
“PRE BLEED”
PRE BLEED mode in progress.
Bleed Valve active
Water discharge before dosing biocide.
No action required.
“PRE BIOCIDE 1”
“PRE BIOCIDE 2”
PRE BIOCIDE 1 or 2 in progress
Output 5-E-N or 6-E-N active
Biocide activator dosage in progress.
No action required.
“BIOCIDE 2”
BIOCIDE 2 in progress
Output 4-E-N active
Killing dangerous organism in progress.
No action required.
“LOCKOUT 1”
“LOCKOUT 2”
LOCKOUT 1 or 2 in progress
Bleed Valve disabled
Bleed mode locked after biocide dosage.
No action required.
“BLEED TIMEOUT” Pre-bleed activity time exceeded Check biocide 1 or 2 menu
Alarm status Message Explanation Action Required
“ALARM” ALARM
Output 10-11-12 active (see contact mode)
Check alarm by rotating wheel in main screen
until to show “Status Alarm”
Once alarm status is xed the instrument will resume interrputed
activities.
Outputs status Message Explanation Action Required
“FEED D1” D1 output active No action required.
“FEED P1” P1 Proportional output active No action required.
“MTOWER PLUS” main display shows more information about plant proper functioning. By rotating wheel clockwise the
instrument will show: “Status Output”, “Status Totalizer”, “Status Level”, “Status Alarm”, “Status Biocide”.
See above table for messages explanation.
“MTOWER PLUS” Operating Status Messages.
Local Date
Local Time
ORP reading
Plant temperature
Conductivity reading pH reading
Outputs status
Alarm status
Conductivity status
Connection Status
LAN Connected - Connected to ERMES
LAN Cable disconnected
LAN Connected - Not connected to ERMES
USB pen-drive connected

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“MTOWER PLUS” status screen.
From main screen rotate wheel (one click - one menu) clockwise for more information about instrument functioning. For
more information rotate the wheel clockwise. The instrument will show: “Status Output”, “Status Totalizer”, “Status Level”,
“Status Alarm”, “Status Biocide”, SERVICE (for ERMES communication).
Status Output
PreBiocide 1 or 2 : Pre Biocide 1 or 2 status
Biocide 1 or 2 : Biocide 1 or 2 status
PreBleed: Pre Bleed status
Inhibitor: Inhibitor status
Bleed: Output status
Alarm: Output status
Status Totalizer (1unit = 1lt)
Water Meter Input: Main water input totalizer
Water Meter Bleed: Bleed water input totalizer
Water Meter Delta: Plant water totalizer (“delta” between
WMI and WMB)
Status Level
PreBiocide 1 or 2 : Pre Biocide 1 or 2 tank level
Biocide 1 or 2 : Biocide 1 or 2 tank level
Inhibitor: Inhibitor tank level
Redox: product level for ORP (HIGH or LOW)
pH: product level for pH (HIGH or LOW)
Status Alarm
High conductivity: HIGH Conductivity Alarm
Low conductivity: LOW Conductivity Alarm
pH High: HIGH pH Alarm
pH Low: LOW pH Alarm
Bleed Timeout: Bleed Timeout Alarm
Flow: No / YES Flow Alarm
mV High: high ORP reading alarm
mV Low: low ORP reading alarm
Off: alarm not active - ON: alarm active
Status Biocide
Week: Week number
Day: dosing day
Next: Next dosing activity
Connection Code for ERMES (through USB cable)
Connection Code for ERMES (through LAN cable)

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“MTOWER PLUS” basic settings.
Basic settings are: PASSCODEs, Time & Date, International Units.
Standard settings are: Probes calibration and operating modes (bleed - inhibitor - biocide).
Advanced settings are: Flow meter, Alarm and Option menu.
All these three settings must be set in order to properly operate the instrument.
PASSCODE for “Setup” and “Probe” menu access.
To grant access into “Setup” menu press the wheel from main screen, choose “Setup” and enter the PASSCODE.
If this is the rst time here then the PASSCODE is 0000 (factory preset). Press wheel 5 times to grant access.
Otherwise press the wheel 1 time and enter the PASSCODE. Numbers can be selected by rotating the wheel.
To set a new PASSCODE choose “PASSCODE ” from “Setup” menu and enter a four numbers code. Click on “EXIT”
and choose “YES” to save request. The new PASSCODE is now ready.
To change default PASSCODE for “PROBE” menu, repeat procedure once into that submenu.
Note: both the PASSCODEs are independent!
Lost PASSCODE ?
Please dont’ forget the PASSCODE (if changed). In the unfortunate event, please call your local distributor for unlocking procedure. There is no way for you to
recover lost PASSCODE.

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Time & Date setup.
To grant access into “Setup” menu press the wheel from main screen, choose “Setup” and enter the PASSCODE.
Move on “CLOCK” and press the wheel.
To end procedure move cursor on “EXIT” and press wheel to proceed to “Save” request screen. Move wheel on “YES”
to save or “NO” to discard changes.
WARNING: when programming instrument (BIOCIDE) check into STATUS menu that DATE
is correct, otherwise dosing accuracy could be affected. In this case set the correct date
and reset instrument (default settings).

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Units setup.
To grant access into “Setup” menu press the wheel from main screen, choose “Setup” and enter the PASSCODE.
Move on “UNITS” and press the wheel.
Once into submenu press wheel twice on “UNITS” and rotate to choose between “US” unit standard or “IS” international
unit standard. See table for differencies.
EUROPE IS (Internationl Standard) USA
Date (DD/MM/YY) Date (MM/DD/YY)
Time 24h Time AM / PM
°C Celsius °F Farhenheit
Liters Gallons
To change conductivity reading scale from uS to PPM move wheel on “MEASURE UNIT” and press it twice.
To end procedure move cursor on “EXIT” and press wheel to proceed to “Save” request screen. Move wheel on “YES”
to save or “NO” to discard changes.

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“MTOWER PLUS” standard settings.
Standard settings are: Probes calibration and operating modes (bleed - inhibitor - biocide).
PASSCODE for “Probe” menu access.
To grant access into “Probe” menu press the wheel from main screen, choose “Setup” and enter the PASSCODE.
If this is the rst time here then the PASSCODE is 0000 (factory preset). Press wheel 5 times to grant access.
Otherwise press the wheel 1 time and enter the PASSCODE. Numbers can be selected by rotating the wheel.
“Calibration uS” menu.
“Calibration uS” menu includes conductivity calibration , temperature compensation and manual or automatic temperature
compensation.Before to begin calibration choose the probe’s scale using FS option (Full Scale)
Conductivity calibration procedure involves a zero calibration (P1) and a 2nd calibration point (P2) that requires a
buffer solution with value near working range. Furthermore TE (Temperature) and CA (Automatica Compensation)
must be set. Note: This procedure assumes that instrument is correctly installed and congured, connected to a
working probe. Calibrate using plant’s temperature otherwise unattended results might occur.
P1 & P2
During this procedure probe must be dry and clean and not installed in plant. Move wheel on “P1” then press wheel,
move cursor on “OK” and press wheel again. Move wheel on “P2” then press wheel to enter into second point calibration
submenu. Prepare buffer solution and dip probe’s sensor on it. Wait until reading value is stable and according to buffer
solution value move wheel until it is the same on display (“uS default” eld). End procedure moving cursor on “OK”.

15
TE & CA
Conductivity measurements are temperature dependent. The degree to which temperature affects conductivity varies
from solution to solution and can be calculated using the following formula: C25 = C / {1+[a/100(t-25)]}
where: C25 = slution conductivity at 25°C, C = conductivity at operating temperature, a = temperature coefcient of
solution %/°C.
Probe read value
(uS or ppm)
Alpha (a) Temperature
(°C / °F)
Displayed Value
(us or ppm)
5227 1.2 35°C / 95°F 4934
4524 3.5 27°C / 80.6°F 4228
3924 2.1 40°C / 104°F 2984
Samples alphas (a) are listed in the table above. To determine that “a” of other solutions, simply measure conductivity at
a range of temperatures and graORP the change in conductivity versus the change in temperature.
“MTOWER PLUS” has either xed or adjustable automatic temperature compensation referenced to a standard
temperature of 25°C. For manual temperature compensation move cursor on “TE”, press wheel and adjust manual
temperature compensation.
Move cursor on “OK” and press wheel again. Move cursor on “CA”, press wheel and choose DISABLE for manual
temperature compensation.
Otherwise for automatic temperature compensation choose “ENABLE” and see “COEFF TEMP” in “OPTIONS” menu
to set % Alpha value.
To end procedure move cursor on “EXIT” and press wheel to proceed to “Save” request screen. Move wheel on “YES”
to save or “NO” to discard changes.

16
“Calibration pH” menu.
pH calibration procedure involves two calibration points and it requires two buffer solutions. Default buffer solutions are
pH 4.00 and pH 7.00. pH reading value can be also 30°C temperature compensated from “CA” eld. From “Probe”
menu choose “Calibration pH”.
In the following example instrument will calibrate pH using default buffer solutions values.
Note: this procedure assumes that instrument is correctly congured and a working pH probe connected.
Otherwise unattended results may occurr.
Calib 1st Point.
Once into “pH Calibration” menu move wheel on “P1” then press wheel to enter into rst point calibration submenu.
Prepare 7.00pH buffer solution and dip probe’s sensor on it. Wait until reading value is stable and according to buffer
solution value move wheel until it is the same on display (“Cal. at” eld). Default value is 7.00pH. To end procedure
move cursor on “OK” and press wheel to proceed to next step.
Note: buffer solution value may change if environment temperature it’s different than 20°C. Read solution’s
label for more information. According to this occurrence “pH Default” must be changed.
pH7

17
“Calibration pH” menu.
Calib 2nd Point.
Move wheel on “P2” then press wheel to enter into second point calibration submenu. Prepare 4.00pH buffer solution
and dip probe’s sensor on it. Wait until reading value is stable and according to buffer solution value move wheel until it
is the same on display (“Cal. at” eld). Default value is 4.00pH.
To end procedure rotate cursor on “OK” and move on TE submenu.
Note: buffer solution value may change if environment temperature it’s different than 20°C. Read solution’s
label for more information. According to this occurrence “pH Default” must be changed.
pH4

18
“Calibration pH” menu.
TE & CA
pH measurements are temperature dependent. The degree to which temperature affects conductivity varies from solution
to solution and can be calculated using the following graphic.
“MTOWER plus” has either xed or adjustable automatic temperature compensation referenced to a standard temperature
of 25°C. For manual temperature compensation move cursor on “TE”, press wheel and adjust manual temperature
compensation.
Move cursor on “OK” and press wheel again. Move cursor on “CA”, press wheel and choose DISABLE for manual
temperature compensation.
Otherwise for automatic temperature compensation choose “ENABLE”
To end procedure move cursor on “EX” and press wheel to proceed to “Save” request screen. Move wheel on “YES” to
save or “NO” to discard changes.

19
“Calibration mV” menu.
ORP calibration procedure involves one calibration point and it requires a buffer solution. Default buffer solution should
be near working value. From “Probe” menu choose “Calibration mV”.
In the following example instrument will calibrate ORP using default buffer solutions values.
Note: this procedure assumes that instrument is correctly congured and a working ORP probe connected.
Otherwise unattended results may occurr.

20
“Calibration mV” menu.
ORP calibration procedure involves probe’s selection with one point (P1) calibration. From “Menu Calibration” choose
“ORP probe”.
Note: This procedure assumes that instrument is correctly congured and a working ORP probe connected
and installed on system. Measurement must be performed using plant water. Otherwise unattended results
might occurr.
Calibration can be performed in two ways: the rst by alignment with a buffer solution, the second by reading the resi-
dual chlorine level of the pool with the DPD1, comparison with the attached graph followed by alignment of the pumps
group. The choice of method is exclusively at the user’s discretion. In both cases, to establish the set-point value, a
check using the DPD1 or other analysis system is necessary. The enclosed graphs provide a reference between the
mV value read by the pumps group and the quantity of residual chlorine expressed in mg/litre, and are linked to the pH
value.
To end procedure move cursor on “OK” and press wheel to proceed to “Save” request screen. Move wheel on “YES” to
save or “NO” to discard changes. If an error occurred during calibration procedure then the instrument will show an error
message and will ask to proceed to a new calibration, cancel current operation or restore default settings.
1) Measure buffer solution temperature and verify that it is
the same printed on solution’s label.
2) Remove protective cap from probe and wash probe’s tip
into water. Then dry it by shaking the probe in air.
3) On “MTOWER PLUS” set “Cal. at” value to match buffer
solution value then put probe’s tip into buffer solution and
wait until “MTOWER PLUS” shows a stable reading value
(mV eld).
4)Move cursor on “OK” and press wheel ton corm the new
calibration value. If calibration process fails the instrment
will show “CALIBRATION FAILED”. Repeat procedure
otherwise move on “ESC” and press wheel.