Table 1 Process Parameters
Parameter Name | Selection | Units or Options | Range |
| Default |
|
|
PROCESS TYPE | %O2 | CARBON, DPT, |
|
|
| %O2, MV |
|
CARB PROC FACT | 150 |
| 0 to 1000 |
DEWPT PROC FACT | 150 |
| 0 to 1000 |
OXYGEN EXPON | 0002 | POWER OF TEN | 0 to 31 |
TC TYPE | B | B, C, E, J, K, N, |
|
|
| NNM, R, S, T |
|
Process Type
Selecting the process type determines what type of calculation the Smart Transmitter is going to do based on the probe millivolt and probe temperature inputs. The default process value for the Smart Transmitter is %O2 with an exponent selection of 2. This is the selection most often used in Boiler control and Combustion applications.
Percent Carbon and dew point are typically processes that are used in steel treating applications. Percent Carbon is the process value most often used for the control of case depth or the percent of carbon in a steel hardening furnace. Dew Point is used in the control for endothermic generators.
Carbon Process Factor
The carbon process factor can be used to adjust the % carbon value. This number takes into account a number of assumptions that the carbon value is based on. Primary among these is the assumed level of CO in the atmosphere. See the Theory of Process Calculation section for a complete explanation of this value.
It maybe necessary to change the apparent furnace carbon as measured by the oxygen probe if this value is different than actual load samples, shim stocks, or gas analysis. The basic rule of thumb is that an increase is the carbon process factor will decrease the apparent carbon level in the furnace. The default value is 150. Typical values can very from 50 to 400. Increase or decrease the process factor until the desired carbon level is achieved. A process factor that is drastically different than normal may be an indication of a failing probe, water or air leak in the furnace, or excess methane present. Refer to probe troubleshooting guides to determine what other factors maybe effecting the carbon value.
Dew Point Process Factor
The dew point process factor is similar to the carbon process factor but is used to adjust the dew point value if dew point is selected as the process value. This number takes into account a number of assumptions that the dew point value is based on. Primary among these is the assumed level of hydrogen in the atmosphere. See the Theory of Process Calculation section for a complete explanation of this value.
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11/14/2006 | Rev. 14 |
