Instrument Site Logs

Each instrument and piece of support equipment (with the exception of the instrument racks and benches) should have an Instrumentation Repair Log (either paper or electronic). The log should contain the repair and calibration history of that particular instrument.

Whenever multipoint calibration, instrument maintenance, repair, or relocation occurs, detailed notes are written in the instrumentation log.

The log contains the most recent multipoint calibration report, a preventive maintenance sheet, and the acceptance testing information or reference to the location of this information.

If an instrument is malfunctioning and a decision is made to relocate that instrument, the log travels with that device. The log can be reviewed by staff for possible clues to the reasons behind the instrument malfunction. In addition, if the instrument is shipped to the manufacturer for repairs, it is recommended that a copy of the log be sent with the instrument.

This helps non-agency repair personnel with troubleshooting instrument problems. Improper recording of instrument maintenance can complicate future repair and maintenance procedures.

The instrument log should be detailed enough to determine easily and definitively which instrument was at which sites over any given time period. If a problem is found with a specific instrument, the monitoring staff should be able to track the problem to the date it initially surfaced and invalidate data even if the instrument was used at multiple sites.

The site log is a chronology of the events that occur at the monitoring station. The log is an important part of station maintenance because it contains the narrative of past problems and solutions to those problems.

Site log notes should be written in the form of a narrative, rather than shorthand notes or bulleted lists. Examples of items that should be recorded in the site log are:

  • the date, time, and initials of the person(s) who have arrived at the site;
  • brief description of the weather (e.g., clear, breezy, sunny, raining);
  • brief description of exterior of the site. Any changes that might affect the data should be recorded
    for instance, if someone is parking a truck or tractor near the site, this may explain high NOx
  • any unusual noises, vibrations, or anything out of the ordinary;
  • records of any station maintenance or routine operations performed;
  • description of the work accomplished at the site (e.g., calibrated instruments, repaired analyzer);
  • detailed information about the instruments that may be needed for repairs or troubleshooting.

It is not required that the instrument and site logs be completely independent of each other. However, there is an advantage to having separate instrument logs. If instruments go in for repair, they may eventually be sent to another site.

Having a separate instrument log allows the log to “travel” with the instrument. Keeping electronic instrument and station maintenance logs at stations and at centralized facilities also has record keeping advantages, but there needs to be a way that these records can be considered official and not be tampered with or falsified.

Newer electronic signature technologies are helping ensure that electronic records can be considered official. It is important, however, that all of the required information for each instrument and site be properly recorded using a method that is comprehensive and easily understood.

Many monitoring organizations have developed standard station maintenance forms that contain all the items to be checked and the frequency of those checks. It then becomes a very simple procedure to use this form to check off and initial the activities that were performed.