How to setup response factors?
Steps to setup response factors
- Go to Settings.
- Click Setting List, and then choose Response Factors.
- Click Create New button.
- On the next screen, choose the instrument model and the substance, input the curve coefficients A and B of response curve
- Click Save.
Knowledge
Portable monitoring instruments (analyzers) used to detect TOC concentration do not respond to different TOC’s equally. To demonstrate this point, consider a monitoring instrument calibrated using a reference gas (i.e. methane). If the instrument is calibrated correctly and is used to measure the concentration of the gas with which it has been calibrated, it will indicate the actual concentration. However, when used to measure other gases for which the monitoring instrument is more or less sensitive than the calibration gas, it will not indicate the actual concentration. To correct for this, Response factors (RF) have been developed by manufactures of monitoring instruments. The instrument manuals usually provide response factor for some chemical substances. If not, you have to develop yours to meet your specific needs.
In LDAR Server, response curve is used to correct a screening value to actual value. The rational equation is represented as:
$$Y = {AX \over {1+{BX\over 10000ppm}}} $$
Where:
- Y is actual concentration in ppm
- X is screening concentration in ppm
- A and B are curve coefficients
Impacts
In LDAR Server, the response factors are used in calculating emissions. If response factors of a TOC substance are not setup, the screening value will be used in emission calculating, which is not accurate and will yield unexpected results.