Honeywell 9782 Series - Manual (Page 140)

Conductivity/Resistivity Analyzer/Controller
Appendix B - 2 9782 Series Conductivity/Resistivity Analyzer/Controller - Operator’s Manual 7/99
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 Cell 2
Process
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.
Parts Flow
Waste Water
Cell 1 Cell 2
Rinse
Water
a/n 23191
Conductivity Ratio =
Cell
Cell
1
2 Typical Ratio Range is 0.1 to 1.1