ECM NH3 5250, Инструкция по эксплуатации, Страница: 23 / 62

19
CAL (Calibrate) Setup Option (AVG, SKEW)

AVG
Raw data is sampled from the NH
3
sensor and the pressure sensor every 5 ms. This data is
averaged by the NH
3
module every 5 ms before being sent to the display head every 5 ms.
This averaging is programmable. There is one averaging filter for NH
3
and one for pressure.
How the averaging filters are used is shown by Equation 1. The averaging filters are user-
programmable and can be assigned values from 0.001 (heavy averaging) to 1.000 (no
averaging).
ParameterAverage
t+5ms
= α x Parameter
t+5ms
+ (1 – α ) x ParameterAverage
t
[Equation 1]
where:
ParameterAverage
t+5ms
= the parameter average at time “t+5ms”
α = These user-programmable filters range from 0.001 (heavy averaging) to 1.000
(no averaging).
Parameter
t+5ms
= the parameter value at time “t + 5ms”
ParameterAverage
t
= the parameter average at time “t”
The default averaging filter values are given within square parentheses in Table 1. These
values and the length of the pressure line assembly should not be modified without first
consulting ECM.

SKEW
SKEW allows the parameters NH
3
, and P to be modified by a programmable transform of the
form:
ParameterSkewed = M x Par B [Equation 2]
where:
ParameterSkewed = NH
3
or P value after being skewed.
Parameter = NH
3
or P measurement before being skewed.
M = Skewing gain. The default values for M are 1.000.
B = Skewing offset. The default values for B are 0.000.
The skewed parameters are displayed and output (i.e. analog outputs, CAN).