A particle counter is a device designed to measure, monitor, and diagnose particles of any substance in a given volume of media like air, water, or other chemicals. They are also used to detect particle contamination in clean media or on surfaces present within controlled environments.
Particle counters are used in numerous industries like pharmaceutical drug products, medical devices, electronic components, and other industrial technologies. They are used in support of clean manufacturing practices. They work on all three mediums and are classified into aerosol particle counters, liquid particle counters, and solid particle counters.
This blog aims to explain what a particle counter is used for and how to choose the ideal one for your industry. It shall also explain the functions of all three types of particle counters in a simplified way. Let us get started.
What do Particle Counters Count?
Particle counters are used to count particles in a given medium essentially to detect any contamination. These particles are usually of sizes that cannot be seen through the human eye. To have an estimated measurement, the particles can be said to be 0.5 µm in size, which is equivalent to a size 200 times smaller than the diameter of a hair strand.
These particles are measured by a particle counter through laser light technology. The device helps in monitoring signs of contamination in cleanroom air. The data collected here are used in critical decision-making processes.
How does a Particle Counter Work?
Particle counters are commonly divided into aerosol particle counters, liquid particle counters, and solid particle counters. Each has different functions.
Let us look at them in the following points.
Aerosol Particle Counters
Aerosol particle counters count the size and number of particles in the air of a closed space and determine its quality. They help in detecting cleanliness levels in a controlled environment or to maintain clean rooms.
Aerosol particle counters are usually of two types- optical and condensation particle counters. Let us look at the functions of each.
Optical Particle Counter
Optical particle counters can monitor particles in both air and liquids. They use high-energy light technology to detect particles by blocking out the light source. An optical particle counter uses the principle of scattering of light to measure particles present in the air. The device can also detect and then measure particles using methods like light blocking, light scattering as well as direct imaging.
Condensation Particle Counter
Condensation particle encounters detect particles by enlarging them up to 200%. They use isopropyl alcohol or butanol to carry out this technology. As the temperature changes, the saturation levels keep fluctuating, and this makes it easier for particle detection.
Technicians can use this monitoring device to detect particles that are as small as 2nm. Such particles cannot be detected even through optical particle counters. Hence, condensation particle counters are required.
Condensation particle counters are the ideal particle counters for clean rooms, as they come in hand-held form models. They have lower flow rates for checking spots and are also certified with lower volumes of air. For monitoring larger air volumes, large portable condensation particle counters can also be installed in clean rooms.
Liquid Particle Counters
Liquid particle counters count the number and size of particles in a particular liquid that is passed through them. They help in determining the quality of the liquid. They are popularly used in checking the cleanliness of drinking water, cleaning solutions, hydraulic fluids, and other liquid sources.
Solid Particle Counters
Solid particle counters measure and detect dry particles that come from sources like rock crushers at mining quarries or from construction sites. They are used for various industrial applications because of their accuracy and efficiency in sizing particles.
How Do You Choose a Particle Counter?
Particle counters are of different types and cater to different needs. Therefore, while choosing a particle counter, there are a few necessary things that one should keep in mind. One must not ignore the size of particles the counter shall count, the specific functions it may perform, and most importantly, the customer’s needs for choosing it.
Let us look at some of the criteria to choose the ideal particle counter.
1. Consider the Size
The first and foremost thing to consider is the size of the particles that are to be measured by the particle counter. This can be easily determined through ISOs which are essentially classes corresponding to workplaces, clean rooms, manufacturing facilities, and other spaces where counter particle installations might be required.
2. Measuring Location
It is crucial to determine whether the particle counter would monitor a specific area at all times or might be taken from place to place according to a customer’s need. If there is a requirement for different spot-check areas for the instrument, it shall require a suitable particle counter that is portable and smaller in size.
3. Check Flow Rate Capacity
To choose a perfect particle counter, the customer must be fully aware of its flow rate capacity. For this, they have to use one of the formulas from the ISO standard and find out the values.
4. Type of Data Collection
A customer should also check the type of data a particle counter collects. This helps with getting accustomed to the measuring units and the instrument’s capabilities before it is actually put into use.
Apart from these, one must ensure that the particle counter they choose has all of the following four components:
- Light Source, which could be either a high-intensity light, laser based on gas, or a solid state laser diode.
- Sample Flow System
- Photo Detection Electronics
- Counting Electronics
Closing Thoughts
Particle counters are great instruments that can make work hassle-free. They are not only efficient devices that make industrial work easy but also help with maintaining cleanliness. With more awareness of their tremendous technology, the use of particle counters is only expected to increase.
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