Hanna Photometric Electrodes

pH, ORP and ISE electrodes are commonly used in potentiometric titrations. These probes produce a voltage that changes as a titrant is dosed into the sample being analyzed. The Hanna family of photometric probes use the principle of absorbance at a specific wavelength to identify the equivalence point of a titration with the use of a color indicator. The color change of a solution causes a sharp change in the absorbance which also causes a sharp change in the mV response. It is common for a complexometric titration to end in a flat mV response. Using the Hanna potentiometric titrator it is possible to program the meter to use the first derivative as the end point. This program is ideal since when a color indicator is used the color change occurs very distinctly.

The use of a photometric probe for potentiometric titration can be used for a variety of complexometric titrations including calcium and magnesium water hardness and iron, aluminum and calcium in cement materials testing. The photometric probe is also ideal for non-aqueous titrations such as Total Acid Number (TAN) and Total Base Number (TBN) of petroleum products due to its advantages over a standard pH electrode.

With the photometric probe there is no fill solution to change in order to be compatible with a non-aqueous sample and there is no pH sensor to foul.