Fall is here and the time is upon us to adjust our clocks back in the kitchen, office desk, watch and automobile. This year Daylight Saving Time (DST) ends on Sunday, November 7th at 2:00 AM and clocks will get adjust . That doesn’t necessarily mean you should be adjusting your Data Acquisition and Handling System (DAHS) time and this topic begs further evaluation and discussion.
Most air compliance regulations are silent when it comes to what time to follow when monitoring, validating and reporting air emissions data. For sources subject to the Part 75 Acid Rain Program (ARP) and for facilities located in the State of Pennsylvania, you are required to have your DAHS maintain Standard Time. Other compliance programs, like AIRS, collect and store data in Greenwich Mean Time (GMT) and provide a conversion to Standard Time. While it may be convenient for facilities to have clocks follow DST, so site personnel don’t need to worry about where to look for data and whether to apply a DST hour offset, it may not be permitted by the regulations affecting your facility or your source.
Managing time in a CEMLink6 DAHS is handled from two (2) independent settings. The first, and most familiar for users of Windows-based computers, is in the Microsoft Date / Time configuration settings. The following image demonstrates what the settings should look like for a system located in the Eastern Time Zone that is NOT following daylight savings time.
The second setting is contained within the CEMLink6 facility configuration screen. It’s imperative that this setting be identical to that of the windows PC that is running CEMLink.
Timestamping data is an integral part of any DAHS. Secondary devices such as PLC controllers, distributed control systems (DCS) or data historians such as PI also play a role how data gets managed. It’s important that you understand if, how and when you should be making DST related adjustments. If you need assistance in determining what time your DAHS is keeping or have any issue with your data that needs to be investigated, please contact our support group at 866-484-6435 or support@vimtechnologies.com.
