ECM NH3 5250, Instruction Manual, Page: 5 / 62

1
Introduction
The NH
3
5250
The NH
3
5250 is a compact, ceramic sensor-based NH
3
analyzer for the development of
engine aftertreatment systems. Its features include:

Single or dual channel NH
3
sensor operation

0 to 2000 ppm range (for lean mixtures only)

Calibration data for NH
3
sensor stored in sensor’s connector

Six programmable 0 to 5V or 0 to 1V analog outputs

CAN output and .dbc generation software

Up to 100 m between NH
3
sensor and display possible

“Lockout” feature for front panel of display

Power on/off can be controlled by external “key” signal

11-28 VDC and 95-250 VAC
1
operation
It is important to realize that when in the exhaust of a running engine, the NH
3
sensor is
seeing H
2
O as just another gas. Therefore, it will report “wet” NH
3
ppm numbers. Classical
gas analysis equipment typically (but not always) has the water removed from the gases
before they reach the analyzer. Thus classical gas analyzers will report “dry” numbers which
are always greater than “wet” numbers. When comparing “wet” to “dry” numbers, make sure
to correct for the removed water.
The NH
3
sensor is designed to be used downstream of a SCR (Selective Catalytic Reduction)
catalyst or where there are not significant amounts of CO (carbon monoxide). This is due to
the sensor’s cross-sensitivity to CO (i.e. 40 ppm CO appears as 1 ppm NH
3
).
1
With optional P/N 04-01 AC/DC Power Supply.