Aquametrix 2200D Dissolved Oxygen Controller/Analyzer User Manual - Manual (Page 16)

Model 2200D/P91 Page 14
5.4 Analog Output Range Expand
5.4.1 The 4-20 mA isolated analog output may be spread over any section of the scale as
long as that section is at least 10% of full scale. The best way to describe this
setup is by example. Suppose you wish the 4-20mA output to span 4 ppm to 10
ppm. Proceed as follows:
a) Press CALL as many times as required until OUTPUT HIGH is indicated. Now
use the arrows to make the meter read 10 ppm. Press ENTER. The display
will flash until ENTER is pressed again to confirm entry.
b) Press CALL once to indicate OUTPUT LOW. Now use the arrow buttons to
make the meter read 5 ppm. Press ENTER twice as above.
c) The analog output will now be at 4 mA when the D.O. of the solution is 5 ppm
and will increase to 20 mA when the D.O. of the solution is 10 ppm.
d) Press RUN to place the instrument on line or press CALL for another menu
selection.
e) To invert the output (i.e. decreasing output for increasing process value) simply
adjust for 4 mA on OUTPUT HIGH and for 20 mA on OUTPUT LOW.
NOTE: A range expand of less than 10% of full scale is an invalid entry which will
be indicated by the LED flashing when you return to RUN. To correct,
return to the menu and correct the output settings.
5.5 Test
5.5.1 To test your setup press CALL the number of times required to indicate TEST. Now
by using the arrow buttons you can “sweep” through the digital display.
5.5.2 With the instrument in TEST you can check the analog output at any desired
reading with a meter connected to the appropriate output terminals.
5.5.3 Another use of this feature is to check the stability of the system. When in TEST,
use the arrow buttons to select any value, say 10 ppm. Now return online by
pressing RUN. Return to the meter some hours or days later. Press CALL to
indicate TEST. If the instrument is still in calibration and if no one has interfered the
meter should read 10 ppm.
5.6 Temperature
5.6.1 The temperature of the process can be read at any time by entering the menu and
calling for TEMPERATURE. Either °C or °F will be indicated depending on the
position of DIP switch No. 1. Bank S1. See Section 4.8.
5.6.2 The 0-5 Vdc and 0-1 mA analog outputs can be dedicated to follow the process
temperature by simply placing DIP switch No. 8 in the off position. The temperature
span of the output is set to the utility menu. See Section 4.8 and 7.4.