Honeywell 9782 Series manual Conductivity/Resistivity/TDS Difference, Parts Rinsing

Conductivity/Resistivity Analyzer/Controller

Conductivity/Resistivity/TDS Difference

Conductivity/Resistivity/TDS difference using redundant cells on critical processes can provide a valuable diagnostic capability. If the difference in measurements exceeds the alarm points, an operator is summoned for corrective action. Monitoring may be switched to the alternate cell during maintenance. For deviation in either direction, two different alarms (+ and -) are used. A difference kind of diagnostic can be provided by a precision check resistor in place of one cell to give continuous Analyzer/Controller checking at one value. See also Appendix D.

9782 Analyzer

Output Signal

Difference Alarm

Cell 1

Process

Cell 2

a/n 23190

Parts Rinsing

Parts rinsing is usually controlled by conductivity to obtain adequate rinsing without wasting excess water, whether a single stage or a counter-current series of tanks. The two-cell ratio approach can determine whether inadequate rinsing is due to low flowrate or due to poor supply water quality.

Cell 2 Cell 1

Parts Flow

Rinse

Water

Waste Water

a/n 23191

Cell1
Conductivity Ratio = Cell2	Typical Ratio Range is 0.1 to 1.1

Appendix B - 2 9782 Series Conductivity/Resistivity Analyzer/Controller - Operator’s Manual 7/99