General principles for process analysis instrument selection
(1) When selecting the process analysis instrument, the media characteristics of the process object to be analyzed, the technical performance of the selected instrument and other restrictions should be thoroughly understood.
(2) The technical performance and economic effects of the instrument should be fully evaluated so that it can play its due role in ensuring product quality and production safety, increasing economic benefits, and reducing environmental pollution.
(3) The technical requirements of the selected analytical instrument detector shall be such as to meet the operating temperature, pressure and material properties of the medium being analyzed, in particular the requirements of all background components and contents.
(4) The technical indicators such as the selectivity, scope of application, accuracy, range, minimum detection and stability of the instrument must meet the requirements of the process, and should be reliable in performance and easy to operate and maintain.
(5) Analytical instruments used for corrosive media or installed in flammable, explosive and dangerous places shall comply with the relevant conditions or meet the requirements for use after taking necessary measures.
(6) Analytical instruments used in control systems whose linear range and response time must meet the requirements of the control system.
Sampling and pretreatment device
1 sampling requirements
(1) The sample taken from the sampling point should be representative and should not cause changes in composition and content after passing through the sampling system.
(6) The material of the sampling tube is generally made of stainless steel. If the sample contains components that corrode the stainless steel tube, other suitable materials such as polyvinyl chloride and polytetrafluoroethylene may be used. Seamless steel tubes can also be used for non-corrosive dry samples. In addition, the sample guiding pipeline should take anti-blocking measures.
2 pretreatment device
(1) The pretreatment apparatus generally includes a condenser, a cooler, a vaporizer, a filter or a purifier, and a chemical or physical treatment means for ensuring the selectivity of the analytical instrument. Its composition should be determined according to the specific sample conditions and the technical requirements of the analytical instrument. Generally, it should be configured by the analytical instrument factory.
(2) After passing through the pretreatment device, the sample should be clean, representative, and free of harmful components, and meet the technical requirements of the analytical instrument detector for the sample.
(3) The concentration or composition of the sample to be tested after passing through the pretreatment device shall not be affected.
3 sample emission requirements
(1) If the measured medium has a recovery value, the sample should be considered for recycling.
(2) A variety of gas samples are emptied. If the components are mixed without danger, and the back pressure fluctuation after mixing has little effect on the analytical instrument, it can be connected to the gas collecting pipe first and then discharged to the appropriate height space. Otherwise it should be emptied separately.
(3) Toxic gases and liquid samples other than water may only be discharged if they meet the requirements of relevant sanitary standards.
(4) The components or piping materials of the pretreatment system shall not react with the sample, will not contaminate the sample, and will not adsorb the components in the sample.
Contact: Cherry
Phone: +86 156 9885 7812
Tel: +86 41183897455
Email: cherry@tereninstruments.com
Add: No75,HuiLi street, HuaNan industrial district,DaLian,China
