For those who have some need of getting secondhand equipment there are distributors who provide them for consumers. They might have things like used electronics test equipment, which are items that are high tech in nature. Monitoring for radio and magnetic fields for physical structures can use these items.
Many experts also rely on this kind of equipment for their needs on the job. Mostly it may be about measuring distances, gradients and the power or force of signals. Electronics rely on signals like these to connect to a network or across a variety of devices in use for an entire system or network.
This system needs to be tested for all values and quantities necessary so that it operates without glitches or interruptions. Most folks who are not engineers or technicians want to have unimpeded signals without knowing how to do it. For radio for instance, DJs do not have the hard job of going out on the field and testing out signals.
The engineers and technicians go out on fields to make things work for the radio network. They spend hours measuring distances and monitoring whether a rock or a stand of trees will affect the way audiences can hear broadcasts. Then they set up the frequencies and angles of broadcast so that the radio station can be effective.
There is going to be a lot of experts using and exchanging stuff, usually because of the need to use other sorts of modulations. Not all items are usable through a long period, especially when they are used in setting up or installations of networks. Thus the electronics guys take care of the stuff they use with a view towards selling them later after a job.
Whenever they need more equipment later this will not mean the same equipment they used before typically. There might be more power needed and the field is not a place they will work in. Usually the calibration work can come after the set up, which requires a new set of items or machines to use.
Gadgets here are really expensive and it will not work out too well to buy brand new devices every time they are needed on occasion. The thing is to sell them off and also take care of them so they are not damaged. The money that is gotten from a sale can go towards buying more stuff that might be needed, also secondhand.
There are still folks that buy the stuff brand new and these add to secondhand or used stuff in the market. There is a premium for these and a good demand at any time and the good distributors all know their clients. Many come back buying or selling their units so they can be more streamlined or do efficient work.
For the most part this is already an established thing for experts here. So that distributors know how the process works for them to know how to provide what they will use. Used units are therefore highly prized in this field.