pH Meter & Sensor

pH is a scale used to specify the acidity or alkalinity of aqueous solutions. The pH value correlates with the concentration (or to be more precise: with activity) of hydrogen ions. Solutions with a pH less than 7 are acidic (high concentration of hydrogen ions) and solutions with a pH greater than 7 are basic (low concentration of hydrogen ions).

There are three essential components for pH measurement:

1. A pH meter capable of measuring a potential in the range of -500 to 500 mV that is transformed into a pH value. For the sake of temperature compensation, an input for a temperature sensor is needed or at least the possibility to enter the temperature manually.
2. A pH sensor consisting of two half cells, a measurement cell and a reference cell, which are normally combined in one shaft (combined pH sensor). The sensor should be selected carefully so as to match your needs. Alternatively, a built-in temperature sensor might be needed (3-in-1 pH sensor).  Sensors without a fixed cable will need the appropriate one to connect to the meter.
   
3. A minimum of two pH calibration buffers is vital. The pH values of the buffers should not differ in less than 2 and more than 3 pH units from each other and cover the whole pH measuring range of your samples. E.g.: for samples in the range of pH 5 to 9, three buffers pH 4.01, pH 7.00 and pH 9.21 (or pH 10) are needed.

Optional accessories are

• Electrode arm (included with most bench meter kits)
• Magnetic stirrer
• Printer
• Refilling and maintenance solutions
• Dedicated software
• Portable equipment such as a carrying case or rubber holster
• Sample changer

This depends on your application. Dedicated single channel meters can be used to measure one parameter like pH, ORP, ion concentration, conductivity or dissolved oxygen). Multi-parameter instruments allow you to measure more than one parameter at the same workplace.

Whatever you need to measure, be it pH, ORP, ion concentration, conductivity or dissolved oxygen (DO, BOD), METTLER TOLEDO, with its years of experience, can provide you with the support you need. Our focus is on high quality products combined with simple, intuitive operation and ergonomic design. The comprehensive product portfolio covers the most varied electrochemical applications in all sectors and offers solutions both for complex applications subject to regulatory control as well as for simple routine measurements.

METTLER TOLEDO offers everything required for precise and reliable pH, ORP, ion concentration, conductivity and dissolved oxygen (DO, BOD) measurements:

• Benchtop and portables meters
• Sensors: pH, conductivity, ion concentration, dissolved oxygen (DO), ORP
• Solutions for calibration and maintenance: Buffers, standards, electrolytes
• Services

Find the best suited Sensor for your application here: www.mt.com/electrode-guide

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