NOSHOK 1900 Series Current Loop Powered Process Indicators - Manual (Page 4)

CALIBRATING THE DISPLAY
Calibrating the 1900C unit requires either an accurate adjustable constant
current supply or the 1900C unit can be installed and scaled with the process
sensor connected to the 1900C unit. To calibrate the unit, proceed as follows.
1. Set DIP switching for the desired current range.
2. Select the desired decimal point position.
3. Apply the minimum input signal to the 1900C unit and adjust the
COARSE OFFSET to display the approximate desired minimum value.
4. Apply the maximum input signal to the 1900C unit and adjust the
COARSE SPAN to display the approximate desired maximum value.
5. Repeat steps 3 and 4 until the minimum and maximum values are within the
desired values.
6. Apply the minimum input signal to the 1900C unit and adjust the FINE
OFFSET to display the exact desired minimum value.
7. Apply the maximum input signal to the 1900C unit and adjust the FINE
SPAN to display the exact desired maximum value.
8. Apply the minimum input signal and verify that the display indicates
correctly.
9. Apply the maximum input signal and verify that the display indicates
correctly.
10. Repeat Steps 6 through 9 until display reads exact.
Note: The 1900C Unit display is factory calibrated to indicate 0.0 to 100.0
with an input of 4 to 20 mA at approximately 25°C.
BLOCK DIAGRAM
DECIMAL POINT POSITION SELECTION
The decimal point position is DIP switch selectable for one of three locations.
The 1900C unit can be set up to read in 10ths, 100ths, or 1000ths. If all the
DIP switches are set to the “OFF” position, no decimal point will appear on the
display. The DIP switches are located at the rear of the unit.
APPLICATION EXAMPLE
Operation of a refinery process required a local display of the position of a
remote pipeline valve. The display would indicate 0 (zero) when the valve was
fully closed with an input signal of 4 mA. When the valve was fully open the
display would indicate 100 with an input signal of 20 mA.
Both the 1900C-1/1900C-2 and the 1900C-3/1900C-4 meet the necessary
TROUBLESHOOTING
For further technical assistance, please contact us.
1900C-2
requirements.
TM190004-1
Corporate Headquarters
1010 West Bagley Road
Berea, Ohio 44017
Ph: 440.243.0888
Fax: 440.243.3472
E-mail: [email protected]
Web: www.noshok.com
INCORPORATED