Probe Calibrations & System Maintenance

It is recommended that your Continuous Monitoring (CM) system undergoes a “major tuneup” at least once annually. Although there are monthly or quarterly alarm checks and preventive maintenance schedules to complete, an annual probe calibration to an NIST or ISO 17025-traceable standard and a comprehensive system check/validation will ensure the system is in good working order.

Annual Probe Calibrations

Your CM manufacturer will issue a Certificate of Calibration for probes that are calibrated to an NIST or ISO 17025-traceable standard. Because the accuracy of probes may degrade or drift over time, it is good practice to ensure they are measuring and reading within specifications. The typical interval for re-calibration of probes is 12 months, which coincides with the annual system maintenance schedule. Table A is a checklist for the calibration of each probe.

Table A – Probe Calibration Checklist

Description

Notes & Comments

Probe Calibration

Either replace expired probe or field calibrate the existing probe to the manufacturer’s specifications.

Certificate of Calibration

A Certificate of Calibration is either issued for each individual probe, or the probe serial number is alternatively listed in a consolidated Certificate of Calibration. In either case, verify the serial number is accurately listed and the expiry date is as expected (e.g., expires in 12 months).

The Certificate should either be maintained electronically in the CM application database or as an original copy with your designated records manager.

Table A – Probe Calibration Checklist (Continued)

#	Description	Notes & Comments
3	Serial Number Updated in Database	If applicable, verify the probe serial number is updated in your CM application software.
4	Expiry Date Updated	If applicable, verify the expiry date is updated in your CM application software.
5	Probe Type	If applicable, verify the correct probe type is selected in your sensor profile or properties page.

Annual System Maintenance

As compared to regular system preventative maintenance (“PM”), where limited-scope checks and inspections are completed, an Annual System Maintenance is a “major tune up.” Table B outlines key end-to-end tests and verification checks to complete during annual system maintenance.

Table B – Annual System Maintenance Summary Checklist

Description

Notes & Comments

Equipment Mounting and Placement

Based on applicable building codes and requirements, and the CM manufacturer’s specifications, verify all equipment is mounted to the manufacturer’s specifications and recommendations.

Transmitters, panels, and other equipment should be mounted at the optimal height, away from potentially damaging environments like water/moisture, excessive heat, cold, humidity, etc.

Table B – Annual System Maintenance Summary Checklist (Cont’)

#	Description	Notes & Comments
2	Wiring Checks	For wireless systems, verify wiring and cabling is within applicable guidelines and specifications. For wired systems, inspect and verify the integrity of wiring to and from equipment panels.
3	Labeling	Verify all monitoring equipment and appliances are properly labelled with the correct asset ID #, and as applicable, appliance name, calibration information, etc.
4	Probe Media & SDS Check	For probes that are immersed in a liquid media, verify the fluid levels are topped off and the media itself has not expired. Verify the bottle is properly labelled and Safety Data Sheets (“SDS”) are current and readily available.
5	Battery Replacement	Although batteries may have been replaced and “have a few more months of life left,” replacing batteries on the annual anniversary is a good practice to minimize the risk of a power loss due to drained batteries.
6	Main Panel Battery Check / Replacement	The wiring panels of a hard wired system oftentimes include a backup battery that needs to be inspected, tested and replaced on the recommended interval.

Table B – Annual System Maintenance Summary Checklist (Cont’)

Description

Notes & Comments

Alarm Checks

Perform alarm checks on all probes to verify standard min, max, and time delay settings. Some organizations elect to perform alarm checks on one quarter of their sensors each quarter. At the end of a 12 month cycle, an alarm check has been completed for every probe. Consult with your CM manufacturer for recommendations.

Some CM systems support multiple set points for alarm and time delay thresholds, in which case additional testing to verify at least a representative sample of points is advisable.

Alarm Notification & Escalations

In addition to trigger high and low alarms, it is also important to verify the alarm notification protocol is as expected. Test procedures should include, at a minimum, the verification of:

All designated recipients receive each notification message and the notification message contents are accurate and correct
Each type of notification (email, SMS text, page, phone call, etc.) is received, in the proper sequence, and for the designated test sensor
Notification escalation protocol is correct

Systems with mobile apps should also verify that users receive alerts and can, as applicable, interact with the CM system via the mobile app and its device (mobile phone and/or tablet).

Table B – Annual System Maintenance Summary Checklist (Cont’)

#	Description	Notes & Comments
9	Line Power	For sensors and equipment that are AC line powered, verify the integrity of the connections and that overloading is not an issue. As applicable, AC adapters may need to be “secured” so that they are not unplugged.
10	UPS Test	For systems on emergency uninterruptible power supplies (“UPS”), verify the expected transition from standard to emergency power is as expected.
11	Emergency Procedures	Review emergency procedures and ensure they are up to date and readily available.
12	Disaster Recovery	As applicable, test and verify that disaster recovery procedures are current and a recovery is successfully completed. Verify system limitations, such as maximum database file size constraints, are not exceeded or close to reaching the limit. Consult with your CM manufacturer for additional recommendations.
13	Application Software Update Verification	As applicable, verify the application software is up to date and is the desired release version. Verify that the latest release of software is the version that you want. Some users elect to forego the latest build in favor of an older or future build.
14	Firmware	As applicable, verify the firmware for all devices is up-to-date and is the desired version.

Table B – Annual System Maintenance Summary Checklist (Cont’)

#	Description	Notes & Comments
15	System Validation	As applicable, perform an incremental or full system validation in accordance with your CM manufacturer’s Operational Verification & Input Calibration (“OVIC”), or equivalent, protocol.
16	User Training & Certifications	Annual user training and certifications are recommended to ensure all end users can optimally utilize the system. Verify the latest training resources (manuals, specifications, online links,etc.) are current.
17	Spare Parts Inventory Check	Verify the recommended quantity of on-site spare parts on-hand and maintenance procedures are current and up-to-date.
18	Record Keeping	Verify all system checks, validation protocols, and maintenance records are up-to-date and available to support applicable reviews and audits.
19	Contact Information Updates	Verify all CM manufacturer or vendor contact information (Sales Representative, Help Desk, Customer Service, etc.) is up-to-date and readily accessible.
20	Other	Each organization’s CM system is unique. Consult with your CM manufacturer to plan for and implement other procedures and protocols that may apply to some or all of your facilities.

In summary, performing your annual probe calibrations and system maintenance is vital to maintaining a system in good working order and ensuring your end users are utilizing the system in an optimal manner. Your CM manufacturer is a key resource and partner in this annual protocol.

For more information on the Keys to Successfully Implementing a Continuous Monitoring System, please check out our full outline, or contact a Mesa Labs representative for a free consultation.

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About the author

Roy Chien

Roy is the Sr. Director of Product Management for Mesa Labs. He is an expert in the field, with an MSEE, MBA and over 12 years of experience in Continuous Monitoring.