ISOLATED CURRENT OUTPUT BOARD ADJUSTHENTS (Optional) (Refer to Fig. 14)
The isolated current card may be configured by means of a jumper to operate from either output
parameter. A jumper also determines whether zero input volts results in zero or four output
milliamperes. Ten volts produces 20 mA in both cases.
To adjust the offset and gain adjustments set switch S4-1 on the processor board for mode 0
operation. Using R35 set meter for zero voltage and adjust R629 for zero current output or 4 mA
output. Using R35 set front panel display to 10.00 and adjust R612 for a 20 mADC output.
If one 4-20 mA output is selected for temperature value transmission, during adjustment of the 4
mA and 20 mA levels the display will be in engineering units. For example, 0:0 display will
correspond to 4 mA and a 50:0 display will correspond to 20 mA. To minimize power dissipation,
the current output terminals should be shorted when not connected to an external instrument.
CHLORINE SENSOR MAINTENANCE
The sensor, like the instrument, is constructed of durable, corrosion-resistance materials. See Figure 4. It is
designed to withstand rough use in laboratories, industrial installations, or waste treatment systems. The
sensor may be used in any water solution, but will be attacked by organic solvents such as chloroform,
benzene, or ethyl acetate. Special sensors are available for use with such materials, and for temperature
extremes. Consult the factory for details.
The only service required on the sensor is changing the electrolyte every 12 months and replacement of
damaged membranes as necessary.
ELECTROLYTE LEVEL: The electrolyte reservoir must be correctly filled for proper operation of the sensor.
Check this from time to time. Hold the sensor vertically with filling screw facing upward, and remove screw. If
necessary, add electrolyte. Use the dropper cap supplied with NO. R-448 Electrolyte and fill the reservoir all
the way to the middle of the pressure proof membrane. There should be a free air space above the electrolyte.
This may be noted on the pressure proof glands on the side of the probe. Replace the screw and tighten firmly.
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