In-Line ph Probe

In-Line pH Probes & Sensors

Reliable In-line pH Probes for Process & Water Applications

In-line pH sensors are analytical instruments designed for continuous measurement of pH in industrial processes. METTLER TOLEDO offers both analog and digital in-line pH sensors that are designed to measure accurately under harsh process conditions, in pure water and withstand high-temperature cleaning and sterilization. In-line pH probes with Intelligent Sensor Management (ISM) offer predictive diagnostics that help reduce maintenance efforts and ensure uptime for your in-line pH measurements.

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How do I select the right pH probe for my application?

For optimal pH measurement, it is crucial to choose the right in-line pH probe for each measurement point. The most important criteria are: process chemical composition, homogeneity, temperature and pressure, pH range and container size (length and width restrictions). The choice of in-line pH probe is of particular importance for non-aqueous, low conductivity, protein-rich and viscous samples where general-purpose glass electrodes are subject to various sources of error. The response time and accuracy of an in-line pH probe is dependent on a number of factors. Measurements at extreme pH values and temperatures or low conductivity may take longer than those of aqueous solutions at room temperature with a neutral pH value.

How do I store an in-line pH sensor?

METTLER TOLEDO in-line pH sensors should always be stored in reference electrolyte. This allows immediate use of the in-line pH sensor when needed, and ensures a short response time. When stored dry for long periods, many in-line pH sensors must be reactivated by soaking for several hours before installation in order to get the optimal measuring results. If these measures are not sufficient, the electrode may be made functional by treating it with a special reactivation solution followed by subsequent conditioning in the reference electrolyte. Do not store an in-line pH sensor in distilled water, as this will cause the pH sensor to have a longer response time.

What is the shelf life of an in-line pH probe?

If an in-line pH sensor is stored at normal room temperature with its original storage cap and solution in place on the end of the electrode, it can last well over a year with no degradation in performance. If the storage solution is allowed to dry or leaks out due to storage at high temperatures, freezing or other causes, the life of the probe may be reduced significantly.

What in-line pH sensors are in METTLER TOLEDO's portfolio?

METTLER TOLEDO has a wide range of in-line pH sensors including:

  • The InPro 2000 family of refillable in-line pH sensors.
  • The InPro 3100 family of in-line pH sensors for biopharma and food and beverage production. 
  • The InPro 3250 family of pre-pressurized, liquid-filled in-line pH sensors that meet the needs of a wide range of industries.
  • The InPro 3300 non-glass, ISFET in-line pH sensor.
  • The InPro 4010 in-line pH Sensor that uses a polymer electrolyte and is ideal for wastewater applications.
  • The InPro 4260 and InPro 4281 families of in-line pH sensor for highly demanding chemical applications.
  • The InPro 4550 and InPro 4501 family with a polymer body for chemical and wastewater applications.
  • The InPro 4800 and In Pro 4881 pH sensors that are designed for strong resistance to oxidizing media, solvents, or sticky contaminants.
  • The InPro 4850i in-line pH sensor for chlor-alkali processes.
  • The pHure sensor and pHure sensor LE for in-line pH measurement in pure water applications.