OMC-042 / 043 / 044 Data loggers
Users
’ manual
page 42
Example 1
A measured tank liquid level could be compensated with temperature and passed throug an equation to
calculate the contents of the tank in kg.
Within the data logger each sensed parameter/channel has a parameter code chosen by the user (e.g.
TEMPC for a temperature in Celsius). These parameter codes can be used in equations by preceding
them with a colon (:). When calculating the parameter codes will be substituted with the last recent
measured values. You could enter the equation
round((:TEMPC*1.8+32)*10)/10
to convert a
temperature in Celsius to Fahrenheit and round the result to one decimal.
Example 2
Assume we measure a river height in m (parameter code LEVEL) and want to convert it to a flow by using
the pre-determined polynomial: (see graph below) y=-0.253x
3
+ 21.675x
2
– 359.14x + 1677.5
Then the formula should be entered as follows: -0.2535*pow(:LEVEL;3) + 21.675*pow(:LEVEL;2) -
359.14*:LEVEL + 1677.5
Supported mathematical functions with one argument:
abs(x)
returns the absolute value of x
Example: abs(10.7)= 10
sqrt(x)
returns the square root of x
ln(x)
returns the natural logarithm of x
exp(x)
calculates the exponent of e to x