The images are processed to find objects of interest such as oil droplets, solids and gas in water. The information gathered provides details such as the number and size of the various particles in the water. This information is called the particle size distribution and is often used for calculation of TSS (total suspended solids).
Once the images have been processed the data is collated and presented to the user.
The processing software will colour code the image, with oil droplets coloured blue, gas bubbles green and solids / particulates red. Not all of the particles are coloured, only those considered in focus. This colouring system enables the user to instantly see what is in the water.
When a sufficient number of images have been captured and processed, then useful statistics can be provided. The colour coding is carried through to the reported data for ease of recognition.
In order to get a accurate measurement only those objects that are in focus are measured.
A combination of the sharpness at the edge of the object and the objects variation in contrast is used to measure if the particle is out of focus.
To distinguish between oil droplets and solids the shape is measured. The shape factor is a ratio of the area of the object to perimeter around the object
Gas in the chamber can be distinguished from oil droplets if the object centre is of a lower contrast than its edges. The ratio of this contrast can be adjusted in order to optimise for the detection of gas.
There are many ways that the size of particles in the water affects the produced water system. Large sand particles have the potential to clog systems, an important issue if you are re-injecting your water. The size of the oil droplets can determine the best removal technique and the presence of gas can have a big effect on separation equipment.
Access to accurate on-line data enables you to make informed decisions and improve the reliability and efficiency of your process.