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Liquid Analysis Sensors
Liquid analysis sensors are the measuring elements that sit in the water or process liquid: pH and ORP electrodes, conductivity cells, dissolved oxygen sensors and chlorine sensors. More than half of the sensors listed here are from ABB, alongside JUMO, Hach, Rosemount and Endress+Hauser. Seven Star LLC supplies these analytical sensors, in in-line, immersion and retractable versions, to water treatment, power and process plants in Oman and the GCC.
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Category guide
About Liquid Analysis Sensors
Liquid analysis sensors are the measuring elements that sit in the water or process liquid: pH and ORP electrodes, conductivity cells, dissolved oxygen sensors and chlorine sensors. More than half of the sensors listed here are from ABB, alongside JUMO, Hach, Rosemount and Endress+Hauser. Seven Star LLC supplies these analytical sensors, in in-line, immersion and retractable versions, to water treatment, power and process plants in Oman and the GCC.
Analytical sensor types in this category
pH and ORP sensors. Combination electrodes with glass or metal measuring elements, in general-purpose, high-temperature and fouling-resistant versions, including hot-tap retractable assemblies that can be withdrawn from a pressurized line.
Conductivity sensors. Contacting cells with stainless steel or carbon electrodes for clean and low-conductivity water, and toroidal (electrodeless) sensors for dirty, corrosive or highly conductive liquids. Insertion, dip-type, in-line and hot-tap mounting styles are listed.
Dissolved oxygen and chlorine sensors. Optical (luminescent) dissolved oxygen probes and free chlorine sensors for drinking water and cooling water. Items from Teledyne, GESTRA and Xylem complete the group.
Selecting an in-line analytical sensor
Four things decide the choice. The first is the liquid itself: its pH range, conductivity, solids, oils and any chemicals that attack glass or the reference junction. The second is temperature and pressure at the measuring point, which set the body material and the mounting style. The third is how the sensor will be removed for cleaning and calibration. A retractable hot-tap assembly allows this without stopping the process, while a simple insertion sensor needs the line isolated. The fourth is the transmitter. Its input must suit the sensor signal, the temperature compensation element and, for conductivity, the cell constant.
What to send for a sensor quotation
Send the parameter and range, the liquid, temperature and pressure, the process connection and insertion length, the cable length and the model of the transmitter the sensor will connect to. For a like-for-like replacement the full model code from the sensor label is the best reference. We check it against the manufacturer documentation and propose the manufacturer’s successor if the model has been discontinued.
What to include in your inquiry
These details let us quote the right item the first time.
- Parameter (pH, conductivity, dissolved oxygen, chlorine, turbidity)
- Measuring range
- Process pressure and temperature
- Installation: inline, immersion or flow-through
- Transmitter model the sensor must work with
- Cable length
Missing some of them? Send what you have. A nameplate photo or an old part number is enough to start.
Brands in Liquid Analysis Sensors
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Request a Quote for Liquid Analysis Sensors
Looking for a specific model, part number or brand in Liquid Analysis Sensors? Send us your requirements and quantities. Seven Star LLC sources genuine industrial equipment for customers across Oman and the GCC and replies with a formal quotation.
- Genuine OEM products
- Supply across Oman & the GCC
- Formal quotation from our sales team
Free, no-obligation quotation · takes about 1 minute
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Frequently Asked Questions
When should I choose a toroidal conductivity sensor instead of a contacting cell?
Contacting cells with metal or carbon electrodes are the right choice for clean water and low conductivity, such as condensate, demineralized water and boiler feedwater. Toroidal sensors have no electrodes in contact with the liquid, so they tolerate coating, corrosion and high conductivity, and are used in acids, caustic, brine and wastewater. They are not suitable for very low conductivity.
What is a cell constant and why does it matter?
The cell constant describes the geometry of a contacting conductivity cell. Low constants are used for pure and low-conductivity water, higher constants for more conductive liquids. The transmitter must be set to the constant of the connected cell, and a cell with the wrong constant for the range gives poor resolution or polarization errors. State the expected conductivity range and we select the constant.
Will a replacement pH sensor work with my existing transmitter?
Check three points: the signal type (analog millivolt or digital), the temperature compensation element built into the sensor, such as Pt100 or Pt1000, and the connector or cable termination. If all three agree with the transmitter input, a replacement normally works. Send the model codes of the old sensor and the transmitter, and we verify the combination in the manufacturer documentation.
What is a hot-tap retractable sensor used for?
A hot-tap assembly lets the sensor be withdrawn through a ball valve while the line or vessel stays in service. It is chosen where the process cannot be stopped for cleaning and calibration, for example on a main header or a continuous reactor. The assembly has a pressure limit for insertion and retraction, so give the operating pressure and temperature with your inquiry.
How do optical dissolved oxygen sensors differ from membrane sensors?
An optical sensor measures how oxygen quenches the luminescence of a dye on the sensor cap. It consumes no oxygen, needs no electrolyte and does not depend on flow past the sensor. A membrane-covered electrochemical sensor consumes oxygen at its cathode, needs a minimum flow and periodic membrane and electrolyte changes. Electrochemical types are still common for very low, ppb-level measurements in boiler water.