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Surface Mount pH Controller Model M05-pH in IP65 Enclosure with 3 x Control Relays and 2 Expandable 4-20mA outputs.

Surface Mount pH Controller Model M05-pH

The M05-pH pH Controller is only available in Surface Mounting Configuration. A number of enhanced versions of the M05-pH are available:-

Model M05-pH-DL pH Controller with built in data-logger.

Model M05-pH-GSM pH controller with built in GSM Modem.

Model M05-pH-RS232 pH Controller with built in RS232 connection for remote operation.

Surface Mount pH Controller Model:- M05-pH Introduction

The model M05-pH controller is a state of the art surface mounting pH controller in a custom made corrosion resistant IP65 housing with separate terminal housing with a gasketed lid.

The Surface Mount pH controller model M05-pH has a custom made 128 x 64 display which displays pH, temperature and the state of the two control relays and common alarm relay all in the same display. 

The M05-pH is a precision instrument which means that it is suitable for a wide array of applications and it is also designed to be as simple to use as possible. The instrument is fitted with 4 way directional buttons which are used to navigate through the onscreen menus. There are two selection keys allowing the user to easily confirm and select each of the functions during setup and calibration. The stated function of each button during each step of the process item is prominently displayed at the bottom of the LCD display. This means that the days of looking through instruction manuals are almost behind us.

The clear graphic back lit display includes a large display of the process units - in this case pH, it also shows the date & time, displays the process temperature, alarm warning display, function menu display, setup menu display, and probe menu display. 

The M05-pH is designed to be a surface mount pH controller and can be placed is some of the harshest environments possible. The robust corrosion resistant ABS housing is designed to meet the IP65 standard and measures 202 mm wide x 201 mm height and 106 mm deep. There are mounting holes 184 mm x 184 mm located in the housing to enable easy mounting to a surface. 

As the pH Controller is designed to be surface mounted to access the terminals the M05-pH has been designed with a gasket lid. This means that the terminals can be accessed easily and without having to remove the M05-pH from the surface to which it is affixed. 

We strongly recommend using the M05-pH with an AWE Instruments pH Electrode or other high quality electrode. To aid the connection of an electrode the M05-pH is fitted with a BNC connector allowing the easy connection of the probe. 

The M05-pH Surface Mount pH Controller works across the full pH range of 0.00 - 14.00 pH and also takes a second input from a PT100 temperature sensor. The temperature input can be from a separate PT100 temperature sensor or from a pH Probe with built in temperature sensor. The temperature reading and automatic temperature compensation (ATC) occurs across the 0 - 100°C range.

For additional safe operation the M05-pH has a flow sensor input which provides an override on the controller to prevent process control should no flow be detected. This is particularly useful on in-line installations. 

There is also a low level input which can prevent to process control from occurring should there be a low level of chemical reagent present. For example if a process is being controlled by the chemical dosing of an acid solution by a metering pump, then should there be a low level of acid present as measured by a suitable low liquid level sensor then the M05-pH will stop the pump from being called. By preventing the pump from operating dry this can prevent damage from occurring to the pump.

Mains supply to the M05-pH is by the built in switch mode power supply. This accepts any mains supply voltage from 100 to 240V AC at 50 / 60Hz which allows the unit to operate fro many overseas locations and simplifies stocking requirements. 

Surface Mount pH Controller M05-pH With Built in Data Logger

The M05-pH is also available as pH controller with optional built in Data Logger. The M05-pH-DL includes a slot for an SD card where the measured pH value and the time of the reading are stored on the SD Card for interrogation by a computer. The data is compatible with Microsoft Excel or Apple Numbers. 

Surface Mount pH Controller M05-pH With RS232 Connection

The M05-pH is available with an optional RS232 connection. The M05-pH-RS232 has an RS232 connection with galvanic separation allows the M05-pH to be remotely controlled from a network connected computer. The software is provided to be installed on a compatible PC for remote operation. 

Surface Mount pH Controller M05-pH With Built in GSM Modem

The M05-pH is also available with a built in GSM / GPRS modem. The M05-pH-GSM has a GSM / GPRS Modem which is able to send you event based messages as an SMS messages should an event be triggered. Where site locations are remote or where the M05-pH-GSM is located far away from a maintenance station this acts as an effective monitoring solution. A number of customer who manage sites on behalf of their customers standardise on the M05-pH-GSM pH controllers; to enable them to include the remote alert system as an additional benefit to their customers service contracts.

M05-pH Surface Mount pH Controller with 3 x Control Relays

The M05-pH controller is fitted with 3 control relays. These are SPST (Single Pole Single Throw) and able to offer On / Off control and are 5 amp inductive. Two of the three control relays have an adjustable hysteresis. In addition these two relays are can be user selected to operate as either On / Off control relays or to offer PWM (Proportional Width Modulation) control.

The PWM relays allow a solenoid valve to stay open for a defined period of time regulating the flow of a reagent proportional to the measured pH value. Typically PWM relays control solenoid valves which allow the discharge of lime or caustic as a reagent.

The third relay is traditonally operated as an Alarm Relay for either high or low operation, where the alarm relay triggers should the pH value fall below a desired pH setpoint in Low mode, or above a desired pH setpoint in High operation mode.

M05-pH Surface Mount pH Controller with 2 expandable 4-20mA outputs

The M05-pH is fitted with 2 expandable 4-20mA outputs which are isolated to 400Ω. The 4-20mA outputs can be both expanded and inverted as required; this means that across the 4-20mA output, it can selected to either represent the full 0 - 14.00 pH scale or a proportion of the range. So for instance the 4-20mA can be set over the 7.00 to 10.00 pH range where a 4mA is produced at 7.00 pH and a 20mA signal is produced at the 10.00 pH value. In this instance the 4-20mA can be connected to a compatible proportional dosing pumps to provide full proportional dosing of acid so that at a value of 10.00 pH the pump is called to dose at it's maximum amount before decreasing the amount of acid dosed as we near the desired setpoint (4mA or 7.00pH).

M05-pH pH Controller Specifications

Input: Any AWE combination pH electrode or other good quality electrode.

Range pH: 0.00 - 14.00 pH.

Display: Backlit Graphic Display LCD 128 x 64

Temp Range: 0 - 100ºC or 14 - 212ºF

Automatic Temp Comp: Automatic via PT100 Sensor.

Manual Temp Comp: Manually Selectable from 0 - 100ºC 

Zero: Adjustable

Slope: Adjustable

Resolution: 0.01 pH.

Control Relays: 

Action: On / Off or PWM (Pulse Width Modulation). High / Low Selectable, SPST, 5 Amp Non-Inductive.

Hysteresis: adjustable.

Alarm Relay: 1

Action: On / Off, High or Low Operation, SPST, 5 Amp Non Inductive.

Current Output: 2 x Expandable 4 - 20 mA (programmable), isolated to 400 ohms, signal selectable.

Flow Sensor: Input by flow sensor and output relays frozen on "No Flow".

Level Control Sensor: Input by liquid level probe and output relays frozen on low level.

Power supply: 100 - 240 V AC 50 / 60Hz. via internal switch mode power supply.

Modem: Optional - GSM / GPRS compatible via sim card. 

Data Logger: Optional - Fitted internal slot for SD Card.

Power Consumption: 10VA

Weight: 1150 grams panel mount version.

Dimensions: 202 x 184 x 106 mm

Ordering: Please Specify model:- 

M05-pH Surface Mount pH Controller 

M05-pH-DL Surface Mount pH Controller with built in Data Logger

M05-pH-GSM Surface Mount pH Controller with built in GSM Modem

M05-pH Data Sheet

M05 Data Sheet

Easy to use pH Controller with 2 setpoints in Weather-Proof Enclosure. AWE Instruments Model P3647-W.

Easy to use pH controller P3647-W with 2 control relays.

The P3647-W pH Controller is only available in surface mounting configuration.

Easy to use pH Controller Introduction.

The Model P3647-W pH Controller is designed to be as easy to use as possible. The setup of the instrument including allocating the two setpoints, calibration and  ensuring the instrument is able to control a wide range of industrial processes has been designed to ensure that it is as simple as possible.

The controller itself is designed to din-rail mounting specification measuring just 105 mm wide x 100 mm high x 58 mm deep. In the surface mounting enclosure the unit measures 135 mm wide x 170 mm high and 115mm deep and we recommend allowing a further 25mm in height for access to the glands for connecting the power cable, pH electrode, and as required the metering pump, or solenoid valve.  

The P3647-W pH easy to use pH controller has a large easy to read LCD display giving good visibility to an operator of the current pH value. The controller has a clear door for easy access to the simple to use controls allowing the operator to calibrate the instrument or set the two setpoints from the front panel. 

The 2 setpoints can be adjusted using the front mounted potentiometers and allow for the on / off control relays to be set for high or low level operation.

The easy to use pH controller is able to work with any glass probes from our pH Electrode range or any other high quality pH electrode. This does exclude the use of antimony pH electrodes. The P3647-W pH controller works across the full 0.00 - 14.00 pH range. 

In addition to the pH measurement the P3647-W easy to use pH controller offers temperature compensation across the 0 - 100ºC range through a NTC10K Temperature Sensor or pH Electrode with built in temperature sensor.

P3647-W easy to use pH controller with 2 on / off control relays

The model P3647-W easy to use pH controller is fitted with two on / off  control relays each with an adjustable time delay of up to 40 seconds before the relay operates. The operation of the model P3647-W pH controllers relays maybe selected for high or low operation by two DIL switches one for each relay.

Enabling the relay functions to be either High - High, High - low or Low – Low.

When the setpoint is configured for use under low operation, then when the monitored pH value is lower than the set-point value, the LED is lit and the corresponding relay is activated. If the relay has the delay function activated then the timer will be called until the relay is activated. 

For use under high operation when the monitored pH value is higher than the setpoint, the LED is lit and the corresponding relay is activated. Again - if a delay has been assigned to the relay then the relay will wait until this delay has expired before activating the relay.

As the P3647-W is an easy to use pH controller with excellent control options it makes an excellent choice of cost effective pH controller for many industrial processes including effluent treatment and water treatment plants. 

P3647-W easy to use pH controller with 4-20mA output

The P3647-W easy to use pH controller has an industry standard 4-20mA output isolated to 500Ω. This 4-20mA output can be used with a variety of control equipment including PLC's and chart recorders. The 4-20mA output in this instrument is non-expandable meaning that the current output is not suitable for use with proportional control dosing pumps.

P3647-W Controller Specifications 

Range pH: 0.00 - 14.00 pH.

Display: 3 1/2 LCD units.

Display Size: 12.5mm 

Temp Range: Compensating 0-100ºC or 32 - 212ºF

Automatic Temp Comp: Automatic 10KΩ NTC Sensor.

Zero: ± 15%

Slope: ±15%

Resolution: 0.01 pH.

Set Points: 2 on / off over 100% of the range. SPST, 2 amp non-inductive.

Action: High Low Selectable, with delay timer 0 - 40 seconds. 

Current Output: 4 - 20 mA isolated to 500 ohms.

Power supply: 50 / 60Hz

Power Consumption: 3VA

Weight: 265 grams DIN rail version.

Dimensions: 105 x 100 x 58 mm

Ordering: Please Quote Model number P3647-W Easy to use surface mounting pH controller

P3647-W Easy to use pH Controller Data Sheet

P3647-W Data Sheet

P7335 Small Sized pH Controller measuring just 96 x 48 x 95mm and fitted with 2 x On / Off Control Relays and 4-20mA Current Output.

p7335 ph controller

The P7335 pH Controller is available in either surface mounting or panel mounting configuration:- 

Model number P7335-W is supplied in a surface mounting enclosure

Model number P7335 pH controller is supplied in panel mounting configuration.  

P7335 pH Controller Introduction

The P7335 pH Controller offers the same functionality as our P7635 pH controller but is housed in a smaller 96 x 48mm housing. This makes the P7335 an excellent solution for when space is limited. 

The P7335 combines powerful functionality and a bright red LED digital display all in a DIN spec housing measuring just 96 x 48 mm and is designed for the DN 47300 standard. This instrument also has a very short case length at only 95 mm allowing the controller to be mounted into compact sized control panels saving on both space and cost.

The P7335 has user selectable ranges allowing it to be used for either the monitoring and control of pH or Redox (ORP) millivolt. The P7335 can be selected for use with pH probes, Redox Probes, or with Antimony Electrodes for pH measurement in solutions containing HF (Hydrofluoric acid)

The range of the instrument is across the full 0 - 14.00 pH scale and from -1000mV to +1000mV for the measurement of Redox (ORP). 

In addition this instrument also has temperature compensation which maybe manually set over the range of 0 - 100ºC or automatically compensated for over the 0-100ºC. The Automatic Temperature Compensation is through the use of either a Pt100 or Pt1000 temperature sensor. These are available from AWE Direct as either a pH Electrode with a built in Temperature Sensor, or as a separate stand alone temperature sensor. 

When measuring pH we suggest pairing our instrumentation with an AWE pH electrode or another good quality electrode. For Redox measurement we recommend pairing the P7335 with an AWE Platinum band Redox Probe or another precision Redox probe.

The P7335-W pH Controller for Surface Mounting

The P7335 is fitted with two programmable on / off control relays. These can be programmed for either high or low operation and have adjustable delay timers. The on / off control relays are SPST 5 amp non inductive.

Within the instrument a pH value can be assigned as a setpoint (such as a value of 7.00pH).

When the pH value is below this point, a control relay will switch allowing a dosing pump to activate or a normally closed solenoid valve to open. When the set point value (e.g. pH 7.00) is reached the control relay will switch again to stop the dosing pump from operating or to return the solenoid valve to closed. In this instance the on / off control relay is set to low. 

As the pH Controller includes 2 x control relays the pH value of the second control relay can be assigned another value. For example this value could be set at 10.00 pH. If the pH is above this value, a second dosing pump or solenoid valve could be controlled to dose an acid reduce the pH value below the 10.00 pH setpoint. This second on / off control relay would be set to high. This setup would ensure that in this treatment example the pH value would remain between 7 & 10 pH. 

In addition to the On / Off control relays the P7335 includes a SPDT 5 amp non-inductive alarm relay with adjustable delay timer. This can be set to operate on both a high and low measured value. The alarm relay is often used to control an audible alarm and / or control beacon. 

4-20mA output for use with PLC's and Chart Recorders.

The P7335 pH Controller has an isolated current output which corresponds to the measuring range selected (either pH Control or Redox Control) and can output either a 0 - 20mA or a 4-20mA signal. The current output is non-expandable and often used with a PLC or Chart Recorder. 

P7335 Controller Specifications 

Range pH: 0.00 - 14.00 pH.

Range Redox (ORP): 0 - ±1000mV

Display: 4 Digit Bright LED.

Temp Range: Measuring and Compensating 0-100ºC or 32 - 212ºF

Automatic Temp Comp: Automatic via 3 wire PT100 or PT1000 Sensor.

Manual Temp Comp: Manually Selectable from 0 - 100ºC 

Zero: ± 2.00pH

Slope: 80% - 110%

Resolution: 0.01 pH.

Set Points: 2 min / max selectable contacts SPST, 5 amp non-inductive.

Action: On / Off with delay timer of 0 - 100 seconds.

Alarm Relay: 1 Min or Max. Contacts SPDT, 5 amp non-inductive.

Action: On / Off with delay timer 0 - 100 seconds.

Current Output:  0 - 20mA or 4 - 20 mA isolated to 600 ohms.

Power supply: 86 - 264 volt at 50 / 60Hz via switch mode power supply.

Power Consumption: 6 VA

Weight: 500 grams DIN rail version.

Dimensions: 96 x 48 x 95mm cutout 92 x 45 mm

Ordering: Please Specify model:- P7335 Panel Mounting pH Controller and P7335-W Surface Mounting pH Controller


P7335 data sheet

P7335 Data Sheet


High Alkaline pH Electrode Model 9037-10B For Sodium Ion Error Reduction 

High Alkaline pH Electrode Model 9037-10B

The  9037-10B High Alkaline pH Electrode has been designed for high pH applications where Sodium Ion Error occurs. For applications where the pH is above a value of 12 and precision pH measurement is critical then we recommend the 9037-10B for Sodium Ion Error Reduction.

High Alkaline pH Electrode Model 9037-10B Introduction

Sodium Ion Error or High Alkaline Error is occurs in very alkaline solutions - that is - solutions with a very high pH value. The ratio of Hydrogen Ions to Sodium Ions is such that most pH electrodes will begin to respond to the concentration of Sodium Ions. As the pH electrode responds to the sodium ions present this causes a millivolt signal to be sent to the pH instrument. This mV signal is effectively a false positive causing the instrument to interpret this signal as a pH value lower (trending towards an acid) than the actual value.

The 9037-10B is designed as a high alkaline pH electrode to specifically combat sodium ion error in pH electrodes giving minimal sodium ion error above a pH of 13. Using a combination of special glass, dome shaped bulb and a special reference filling material we have minimised sodium ion error in our pH electrode.

The 9037-10B is a sealed double junction pH electrode with ceramic annular peripheric reference junction and domed glass bulb for precision readings and rapid response. The double junction protects the pH electrode against electrode poisoning and the special glass and filling solution give precision results at high alkaline / high pH values to minimise sodium ion error.

High Alkaline pH Electrode Model 9037-10B Features & Benefits.

The 9037-10B is designed to combat sodium ion error at high pH values in excess of 13 pH.

The 9037-10B offers excellent repeatability, a non-fouling peripheric annular double junction which is resistant to electrode poisoning. The glass bulb and special reference solution are designed for use in high alkaline applications to minimise sodium ion error. The dome shaped glass bulb gives a quick response time and is designed to ensure that it can operate this way at a pH above 13.

This is pH electrode has been uncompromisingly designed for high alkaline solutions to reduce sodium ion error, as such it is only suitable for a pH range of 2 - 14 pH and at temperatures of 0 - 100°C.

The 9037-10B pH electrode is widely used with our pH controller range, our inline electrode holders and our portable pH meters.

The mounting cap on the Low Conductivity pH Electrode model 9037-10B is Ryton with a small flange for mounting the pH electrode into our PES style holders.

High Alkaline pH Electrode Model 9037-10B Connection Types and cable length.

The 9037-10B pH electrode is available with a number of connection types; as standard we supply the 9037-10B with 3 metres of connecting cable and a BNC fitting.

For custom fitting types please see the below table for the ordering number and options:-

9037 - XX - Z

High Alkaline pH Electrode for reducing Sodium Ion Error - Model Number.


Cable Length

10 = 3 Metres

20 = 6 Metres

30 = 9 Metres


Connection Type

B = BNC Connector (Most Common)

T = Stripped & Tinned Connections

S8 = S8 Connector (No Cable)

A = U.S. Standard Connector fitted to older U.S. pH Instruments

I = Din 19262 Connector for German pH Instruments

K = Belling Lee Connector for older U.K. pH Instruments

More information on pH electrode connection types

The 9037-10B Double Junction pH Electrode maybe used as a replacement for many other manufacturers electrodes, often outperforming the original electrodes. 

Double Junction pH Electrode 9037-10B In Summary

Range pH: 2 - 14 pH

Operating Temperature: 0 - 100°C

Response Time: Quick

Electrode Type: High Alkaline pH electrode for reducing Sodium Ion Error, sealed double junction, special glass & special reference filling material.

Reference Type: Double Junction with non mercury reference.

Junction Type: Non-Fouling Peripheric Annular Ceramic Type.

Dimensions: 110mm Long  x 12mm ∅

Model Numbers Available Ex-Stock:

9037-10B - Glass pH Electrode with 3 metres connecting cable & BNC fitting.

9037-10T - Glass pH Electrode with 3 metres connecting cable & stripped and tinned connections.

Ordering: Please Specify model using 9037 and then the naming convention defined in the above table for cable and connection type.

pH Electrodes Data Sheet

pH Electrodes Data Sheet




AWE Direct News:- New Teflon Junction pH Electrodes and Redox Electrodes

We are now able to supply our P8000-10B series high performance combination pH electrodes with a porous teflon liquid junction, and our R8000-10B series of high performance combination redox electrodes with a porous liquid junction.

The new range of P8000 pH Electrodes and R8000 Redox Electrodes are ideal for solutions which are incompatible with ceramic. Some chemical blends involving strong acids or strong alkali solutions can slowly dissolve the ceramic junction. Other substances can block the ceramic junction such as biological effluents which contain fats, oils or greases. 

The P8000-10B porous teflon liquid junction pH electrodes and R8000-10B high performance liquid teflon junction redox electrodes aim to eliminate these concerns. 

More about our P8000-10B High Performance pH Electrodes and R8000-10B High Performance Redox Electrodes