Discussion
Why does a typical NDIR analyser use a reference cell as well as a sample cell?
Answer: B
Passing a matched beam through a sealed cell of non-absorbing gas gives a reference against which source ageing, window fouling and detector drift largely cancel, since both beams suffer them equally. Some designs achieve the same end by switching one beam between two paths. It adds no range, performs no sample conditioning, and holds no calibration gas. Ratio measurement of this kind is the standard defence against slow drift in any optical analyser.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development