So you have been tasked with purchasing a temperature monitoring system? More broadly an environmental monitoring system. The difference is that many of these systems can monitor many different variables of the environment such as humidity, the presence of liquids, or even motion. There are a ton of options out there and making the wrong decisions can lead to years of headaches, missing data, and endless tech support. This is s quick guide to help you make your decision. It is not sponsored by anyone and comes from years of working with these systems.
1. Monitor what you need not what you can
The biggest mistake you can make is to not understand what you truly need to report on. If this is a compliance requirement for a customer or government body find out what exactly you need to monitor. A major mistake people make is over building their system. In some cases the server software is the expensive portion and the sensors are relatively affordable. This causes many people to justify the expense of the server by monitoring every nook and cranny of a building.
Once you start reporting on an area during an audit this overbuilding will cause more points of failure. If you are required to have 4 areas monitored and you put 30 sensors in place during an audit you will still need 30 points of reference. Many times one failed sensor is seen as out of compliance and a failure in the system. This depends on the entity performing the audit but mostly I have seen them compare to the last performed audit. Hiding failed sensors from the report can also be flagged even if you still meet the criteria of 4 points of data.
2. Wireless is not your friend
Many systems offer wired tag readers and wireless monitoring tags. These tags sometimes quote 5 year batteries and very long quoted ranges. In some environments and especially in manufacturing RF interference is rampant.
Bailers, conveyors, and warehouse lighting all produce large amounts of interference. This will result in lost sensor data and inconsistent reports. These are some of the most common systems but often times can result in major headaches.
If you have your choice pick a system that is POE directly to the sensors. This will cost a bit more in wiring cost but you will be happier in the end. The data is sent via wire directly from the device and power is delivered to it. There are no batteries to replace and no wireless interference to overcome.
3. Research the company
There are a lot of small companies offering environmental monitoring and some are far better than others. You want to look past the glamorous features in a system and find out what the company behind them is all about. Here are some important questions to answer.
- How big is the company? Number of employees? Number of customers?
- How long have they been around?
- What are the hours of their service desk?
- What warranty do they have on their products?
- Although hard to find try to get reviews or customer testimonials of the system in question?
I have had terrible time with smaller companies in this field where there are only a handful of resources to help with problems.
4. Certification Requirements
If you application is in a lab or deals with primary packaging perishable food you may need a system that is NIST certified. If NIST is not a requirement you also may need to recertify your sensors at a given interval. This can generally be handled internally or the system may have a procedure for outside companies to come in and test each sensor with calibrated equipment. In extreme cases the system will have calibration files that will be issued by the company after proof of a calibration check. Understand the requirements for your application and choose a system that meets your criteria.
It is also a good practice to find out what costs are associated with the recalibration of your temperature readers.
There are other considerations like data retention, database backend, reporting, and alerting options. Now days any good system will offer email, text, and even audible and visual alerts. If there is interest I may write another article describing the other areas that can be monitored with these systems.
If you have any questions or are struggling with your choice drop me a comment below and I will try and answer them to the best of my ability.
I hope this was helpful. Erik