天津鸿河科技有限公司，颗粒计数器生产厂家

The pollutants in fluid systems mainly include water, air, and solid particles. According to the different measurement methods of pollutants, pollution measurement methods can be divided into water pollution measurement methods, air pollution measurement methods, and particle pollution measurement methods.

Measurement methods for water pollution

SHUI WU RAN

The commonly used measurement methods for water pollution in fluid systems include distillation, temperature and humidity, and Karl Fischer method.

Distillation method: The experimental standard used is GB260-1977 "Determination of Moisture in Petroleum Products". During measurement, a certain volume of liquid sample and solvent are first injected into a flask, shaken evenly, and then heated for distillation. The water vapor evaporated from the liquid sample condenses in the condenser and is collected in the receiving tube until the volume of water in the receiving tube no longer increases.

Temperature and humidity method: mainly used for online monitoring of water content in fluid systems. Its working principle is that the water saturation of the fluid has a logarithmic relationship with temperature, while the water content has a linear relationship with relative saturation (relative humidity) and water saturation. Temperature and relative saturation are measured by temperature and humidity sensors installed in the fluid system, and then calculated according to the formula.

Karl Fischer method: Currently, it is the most classic and accurate method for measuring water content in the laboratory, with two methods: titration and coulombic titration. Suitable for the determination of water content in many inorganic and organic compounds.

Measurement methods for air pollution

KONG QI WU RAN

There are three different states of air in fluid systems: free large bubbles (such as air in the upper part of pipeline devices), uniformly suspended small bubbles, and air dissolved in the system. The measurement results of air pollution are commonly expressed in terms of gas content.

The measurement of free large bubbles involves setting a vent valve at a high point in the system to determine the gas content by measuring the volume of the released gas;

The measurement methods for uniformly suspended microbubbles include turbidity meter method, sound velocity method, and volume compression method;

The measurement methods for air dissolved in the system include vacuum pressure difference method and vacuum release method.

Particle pollution measurement method

KE LI WU RAN

Solid particles are the most important and harmful pollutants in fluid systems, therefore particle pollution measurement methods are the most researched and highly concerned methods in fluid system pollution measurement. The commonly used methods for measuring particle pollution can be divided into gravimetric analysis, particle counter method, and other analytical methods.

Weight analysis method: The measurement results can only reflect the total mass of solid particles contained in the fluid, and cannot reflect the size and size distribution of particles; The weight analysis method often fails to obtain accurate results for samples with low particle content.

Particle counting method:

Microscope counting method:The filter membrane filtration device is used to collect particles in a certain volume of fluid on the filter membrane, and then the size and quantity of particles on the filter membrane are counted under a microscope. The microscope counting method can be divided into optical microscope method and electron microscope method according to different analysis equipment. This method can intuitively observe the actual shape and size of particles, and roughly determine the type of particles, without being affected by bubbles in the liquid sample. However, it has high requirements for air environment (at least level 7 in accordance with GB 50073), long measurement time, high operator proficiency, and poor measurement repeatability.

Liquid particle counter method:Firstly, methods such as shaking and ultrasonic vibration are used to uniformly disperse the liquid sample. Then, a sampling device is used to pass the liquid sample through the particle sensing area at a constant flow rate, and the instrument automatically counts the size and quantity of particles in the liquid sample. Due to its short measurement time, accurate results, and good repeatability, this method is currently the most widely used and primary measurement method for particle pollution.

Other analytical methods:

Microscopic comparison method:Using a filter membrane filtration device to collect particles in a certain volume on the filter membrane, and then placing both the filter membrane and the standard contamination level sheet under a comparative microscope to compare the particle size distribution under the microscope, select the appropriate standard contamination level sample. When the particle distribution in the left and right fields of view is basically the same, the contamination level of the standard sample sheet is selected as the contamination level of the measured fluid.

Electromagnetic method:It can be used to measure the size, properties, and quantity of particles, with a lower limit of 70 μ m for ferromagnetic particles and 280 μ m for non ferromagnetic particles. Electromagnetic method is mainly used for online detection of metal abrasive particles.

Optoelectronic method:The measurement is the particle weight pollution level, with a measurement range of (1-250) ㎎/L.

Online Particle Counter

Desktop Particle Counter

Portable particle counter

在线表单

A Brief Discussion on Measurement Methods and Main Characteristics for Fluid Pollution