YSI 5000, Руководство по обслуживанию

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YSI Incorporated Model 5000/5100 Service Manual 29
To calculate the current pressure calculate the difference between the cal point and the current
reading. Divide the difference by 1.11E-5 (assuming a 4v A/D reading = 65800 counts) and the
result is the pressure change from the calibration point in mbar.
DO
Two electrode polarographic DO sensors are with the Anode to J5 pin 2 and Cathode to J5 pin 3.
The Anode is biased positive to approximately 800 millivolts from U22 by selecting the 800 mV
tap on resistor divider R61, R62, R63 through switch U25 section A and B. The Cathode current
is integrated by U22 and C48.
A/D
The input to the analog to digital converter is selected by the multiplexor U23. The gain applied
before conversion is adjusted by selection of the feedback tap on the resistor string R53, 54, R64-
68, and R79.
Dual slope integration conversions are performed with U27 under timing control of U5.