WaterTechw² pH8000 pH and Temperature Sensor

Combined Sensor for pH and Temperature Monitoring

Measuring pH is a vital part of control systems throughout water, wastewater and process industries. In activated sludge plants, the biological process is greatly influenced by the acid or alkaline condition of the mixed liquor, on-line control is vital to maintain effluent quality. In effluent discharge regulations, pH is the most common water quality parameter, giving vital feedback on plant performance and protecting the environment from pollution events. In sewage and industrial effluent treatment, pH control is vital for ensuring that pollutants are removed effectively. When the pH moves away from a neutral position the biological activity of the bacteria reduces, at less than 5pH or greater than 10pH then the activity ceases and the treatment system will start to breakdown. In combination with the 7300w² Monitor we provide the monitoring and control functionality to ensure that the control system remains functional and is carried out in the most cost effective manner.

pH monitoring and control also plays a vital role in the success of potable water treatment. If the water is acidic (lower than 7), lime, soda ash, or sodium hydroxide is added to raise the pH. Lime is commonly used for pH adjustment for municipal water, or at the start of a treatment plant for process water, as it is cheap, but it also increases the ionic load by raising the water hardness. Making the water slightly alkaline ensures that coagulation and flocculation processes work effectively and also helps to minimize the risk of lead being dissolved from lead pipes and lead solder in pipe fittings. Acid (HCl or H2SO4) may be added to alkaline waters in some circumstances to lower the pH. To ensure correct treatment, it is necessary to monitor as well as control the optimisation of the chemical dosing. The WaterTechw² pH8000 sensor has been designed to provide highly reliable operation across the range of drinking water and wastewater applications. The flat faced electrode included the latest innovations in double junction reference with the ERP reference path. We also offer a version of the electrode that is designed to monitor pH in low conductivity (low ionic strength) applications.

When used in dip format the WaterTechw² pH8000 sensor can be supplied with a shaft assembly and accompanying handrail/wall brackets. These parts have been designed to be suit the majority of installations, alternatives and bespoke solutions can be supplied if necessary. Shaft lengths up to 3 metres are offered as standard with longer lengths being catered for when required subject to safety and shipping considerations. For installation in applications where gross fouling is anticipated we recommend that the sensor is installed using our specially designed mounting system, with a flexible joint in the mounting shaft. The flexible joint moves the sensor in the process, reducing bio-fouling and allowing rags to fall away from the assembly. This motion is similar to that achieved by using a floating ball assembly, with the added advantage of placing the sensor below the surface of the liquid.

Our flowcell assemblies are intended for applications where it is not possible to gain direct access to the sample using a dip sensor, these are typically applications in drinking water and final effluent discharge. The flowcell has been designed to take a small positive pressure (1Bar) however the outlet from the unit is normally fed to drain. Multiparameter Options The WaterWatch² platform has been designed to accommodate multiple sensors and multiple parameters in the same 7300w² Monitor. Versions of this flowcell are available to combine pH measurement with Turbidity, Redox and DO. These combinations provide an extremely cost effective way of monitoring for regulatory or control purposes.

Applications

  • Activated Sludge Control
  • River Quality Monitoring
  • Discharge Monitoring

Applications

  • Coagulation Control
  • Final Water
  • Industrial Effluent

Technical Specification

Physical - Dip

Dimensions60 mm diameter x 270 mm long
Weight0.95 kg
Protection ClassIP68
Material of ConstructionPVC Body, pH Glass
Cable EntriesIntegral Cable Gland
Cable Type4 core, Polyurethane Coated
Cable Length10 metres standard, 100 metres maximum
Service RequirementElectrode Replacement
Periodic Cleaning and calibration are required at a frequency determined by the application

Physical - Flowcell

Dimensions235 x 310 x 155 mm (HxWxD)
Weight0.35 kg
Protection ClassIP68
Material of ConstructionBlack Acetal Co-Polymer with Stainelss Steel Mounting Plate, pH Glass
Cable EntriesIntegral Cable Gland
Cable Type4 core, Polyurethane Coated
Cable Length10 metres standard, 100 metres maximum
Service RequirementElectrode Replacement
Periodic Cleaning and calibration are required at a frequency determined by the application

pH Measurement

Principal of OperationCombined Electode (pH/reference) - Ag/AgCl
Double Junction ERP Reference
Accuracy+/- 0.05 pH
Resolution0.01 pH
Range0 - 14 pH

Temperature Measurement

Temperature MeasurementsNTC
Accuracy+/- 0.5ºC
Resolution0.01ºC
Range0- 50º C

Environmental Data

Operating Temperature 0 - 70ºC
Storage Temperature 0 to 70ºC
Location Indoor/Outdoor

Interface to Monitor

Sensor OutputModTechw², RS485
Power12 VDC from Monitor
Information to Download