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This analyzer is the most complete pH/ORP analyzer on the market. Almost all commercially available sensors can be connected, which makes the change towards PH450 easy. Yokogawa understands the implications of switching from one supplier to another, because there is not just the instrument to consider, but also the installed base of the sensors and the safety stock of sensors that users must keep to secure measurements.
Therefore the PH450 comes with two high impedance inputs, with freely selectable Isopotential point and sensitivity. Accurate temperature compensation is offered for six different temperature elements to assure compatibility with all Yokogawa pH/ORP sensors as well with third party sensors that are common in the industry.
The PH450 is perfectly suitable for normal pH or ORP analysis using low impedance reference cells, but can also be used for special configurations, that offer better performance under certain ( normally severe) process conditions:
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Differential pH measurement. Here the reference signal is a high impedance sensor: sometimes a pH sensor in a constant pH buffer solution or a pNa sensor that gives an output that does not vary with pH.
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pH compensated ORP measurement. It is not always understood that every ORP sensor responds to pH changes as much as it does to changes in concentration of oxidizing or reducing reagent. This complicates ORP control unnecessarily. This can be easily overcome by using a pH sensor as reference element for the ORP measurement. PH450 features dual high impedance inputs and 21 points output table, so it is easy to have an output signal linear to the concentration of the reagent.
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Simultaneous pH and rH measurement. In water treatment it is common that both ORP and pH must be controlled. Yokogawa believes in Simple is Best Philosophy, so only one sensor and one analyzer is needed for this dual application. With two current outputs and four contact outputs there are no limitations on the output side to have two applications in one installation.
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It is well known that pH measurement takes place in aqueous solutions. It is also common knowledge that the dissociation of water causes a high temperature drift for most pH applications in alkaline pH range.
Surprisingly Yokogawa is the only supplier that offers full temperature compensation for the influence that the dissociation of water has on the pH value of your process. It is sufficient to select NEN6411 temperature compensation method to activate this function.
Applications where there is a high concentration of weak acids or alkalis PH450 offers also the possibility of MATRIX temperature compensation.
Long term accuracy with a minimum of maintenance is achieved by sensor diagnostics using Yokogawa’s patented impedance monitoring optionally coupled with automatic sensor cleaning.
Dynamic sensor monitoring during cleaning avoids wasting expensive cleaning liquid, disturbing process samples and yet achieving full cleaning of the sensor.
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