Drakkith said:The uncertainty? What do you mean?
An opacity meter, also known as a smoke meter, is a device used to measure the amount of light that is blocked or scattered by particles in a gas or exhaust stream. It works by shining a light beam through the gas and measuring the amount of light that is transmitted through or reflected by the particles.
The main sources of uncertainty when using an opacity meter include variations in the measurement technique, instrument calibration, and environmental factors such as temperature and humidity. Additionally, the type and concentration of particles in the gas can also affect the accuracy of the measurement.
To improve the accuracy of opacity meter readings, it is important to follow proper measurement techniques and regularly calibrate the instrument. It is also helpful to minimize environmental factors and ensure that the gas sample is representative of the exhaust stream being measured.
No, opacity meters are primarily used to measure the emissions from diesel engines and other sources that produce visible smoke. They are not suitable for measuring the emissions from sources that produce primarily gaseous pollutants.
Yes, there are alternative methods for measuring emissions such as using continuous emissions monitoring systems (CEMS) or using other types of instruments such as gas analyzers. However, opacity meters are still commonly used due to their simplicity and relatively low cost.