The major prerequisites of efficient online analysers are:

1. Should be capable of operating unattended over prolonged period of time.

2. Should produce analytically valid results with precision and repeatability

3. The instrument/analyser should be robust and rugged, for optimal operation under extreme environmental conditions, while maintaining its calibrated status.

4. The analyser should have inbuilt features for automatic water matrix change adaption.

5. The instrument / analyser should have onboard library of calibration spectras for different industrial matrices with provision of accumulating further calibration matrices

6. Should have data validation facility with features to transmit raw and validated data to central server.

7. Should have Remote system access from central server provisioning log file access.

8. Should have provision for Multi-server data transmission from each station without intermediate PC or plant server.

9. Should have provision to send system alarm to central server in case any changes made in configuration or calibration.

10. Should have provision to record all operation information in log file.

11. For each parameter there should be provision for independent analysis, validation, calibration & data transmission.

12. Must have provision of a system memory (non-volatile) to record data for at-least oneyear of continuous operation.

13. Should have provision of Plant level data viewing and retrieval with selection of ethernet, wireless, Modbus & USB.

14. In case of TOC analyser, the empirical relationship between TOC to COD or BOD must be authenticated for all industrial applications and the correlation calculation (for factor) provided.

15. The correlation/interpretation factor for estimating COD and BOD using UV-Visible Absorption Technique shall be regularly authenticated/ validated and details provided.

16. Record of calibration and validation should be available on real time basis on central server from each location/parameter.

17. Record of online diagnostic features including sensor status should be available in database for user friendly maintenance.

18. Expandable program to calculate parameter load daily, weekly or monthly basis for future evaluation with flow rate signal input.

19. Must have low operation and maintenance requirements with low chemical consumption and recurring cost of consumables and spares.