ECM NH3 5250, Instruction Manual, Page: 20 / 62

16
dISP (Display) Setup Option (P1 to P14)
Parameter information from the NH
3
module assigned to the upper channel can be displayed
as parameters P1 through P7. Parameter information from the NH
3
module assigned to the
lower channel can be displayed as parameters P8 through P14.
The parameter selected as P1, P2, etc can be anything from Table 2.
Here is an example of setting displayed parameter P2:
1. Press the SYS key until “MOd” is displayed.
2. Press the

key until “dISP” is on the top display. Then press the ENT key.
3. Press the

key until “P2” is on the display. Then press the ENT key.
4. Press the

or

key until the parameter (see Table 2) that will be P2 is displayed.
Then press the ENT key.
5. When “dISP” is displayed, press SYS to return to RUN mode.
If in the above example, displayed parameter P8 was being programmed, dISP, P8, and your
entries will be shown on the bottom display.
CAL (Calibrate) Setup Option
NH
3
sensors supplied with the NH
3
5250 are factory calibrated. This factory calibration is
stored in a memory chip inside the sensor’s connector. With use, NH
3
sensors can age
requiring recalibration to maintain measurement accuracy. Recalibration can be performed
by the user or by sending the sensor back to ECM.
The NH
3
ZERO and SPAN functions are for the recalibration of the NH
3
sensor. This
recalibration is stored in the sensor’s memory chip and is used instead of the factory
calibration. The FACT function cancels the user calibration and reverts the sensor back to
using the factory calibration.
ZERO
To perform a ZERO:
1. A zero should be performed after the NH
3
sensor and pressure sensor (if so equipped)
have been on for at least 20 minutes.
2. Put the NH
3
sensor and pressure sensor (if so equipped) in ambient, stationary air or
in the exhaust of an engine with zero NH
3
.
3. Press the SYS key until “MOd” appears.
4. Press the

key until “CAL” is on the display of the channel to be calibrated. Then
press the ENT key.
5. Press the

key until “NH3” appears. Then pressure the ENT key.
6. With “ZERO” on the display, press the ENT key.
7. Using the

and

keys, change the display to read 0 ppm. Press the ENT key.
8. Press SYS to return to RUN mode.
9. The user calibration is written into the memory chip in the NH
3
sensor’s connector
and will be used to calculate NH
3
. If the NH
3
sensor is removed and installed on