RFID Journal Staff asked 15 years ago I was wondering if there was either an RFID tag that could be deactivated permanently with a large decrease in pressure (namely, if you put a tag in the clamp of a bolt, that would be deactivated when the bolt was removed), or an RFID tag that could be activated by a loss in pressure (namely, if the tag was once again put in the clamp of a bolt, but was activated by the removal of said bolt, thus informing me that the bolt had been removed)?
—Justin, Canton, Ohio
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Justin,
To my knowledge, there is no such tag available on the market. One could probably be created, but custom solutions are usually expensive. Is there another way to achieve the same aim more effectively? Could a reader be put in the clamp to activate and deactivate the tag?
Mark Roberti, Editor, RFID Journal
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The bolt that I am looking to implement this on has a head width of 0.5 inches. Would a reader be small enough to fit in this confined of a space? Also, how much force can the reader handle?
Justin
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It would be tough to get something that small. What if you put a small HF tag on the head of the bolt and an interrogator near where the bolt is located? When the bolt is removed, the reader would no longer detect the tag. Would that work? (Sorry, I don't know the scenario, so I'm trying to figure out how this is going to work in action.)
Mark
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Yes, that could possibly work. I am sorry I do not know the basics about RFID tags, but can the reader keep a record of any failure to detect the tag, or would it be able to read that the tag was removed and then disable the tag? I ask this, because when our trailer suspensions go out in the field, mechanics perform their routine maintenance at regular intervals. The problem is that they usually remove the hubcap to access the interior of the wheel end.
In doing so, they usually do not place the hubcap correctly, or they clamp the bolt to the required torque, thus voiding their warranty. So I am trying to devise a system that would allow us to tell if the hubcap had been removed at any time since we had last had our hands on it. As such, the reader would have to be able to tell us if a mechanic had removed the bolt a week ago, a month ago, or maybe even a year ago. What capabilities does the reader have?
Thank you for your continued help.
Justin
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You could put a small HF interrogator in the wheel well, and a tag in the hubcap. When the hubcap is removed, the reader would ping the tag continually and detect the time the hubcap was not there, and there was thus no response from the tag. It would also record the time the hubcap was not present via the gaps in the reads.
You could download this data from the reader. Every interrogator reads the tag and puts a time and date stamp on every read. The device could be hooked up to a telemetry system to broadcast the info back to a base station, and software could be written to identify significant gaps in the reads, indicating removal of the hubcap.
If RFID Journal's readers have any thoughts on how this system might work, or have implemented something like this, we welcome your input.
Mark
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