Well, what - if anything - isn't? That is the question. Anyway, read the article for yourself first.
If I have a criticism of the article, it's that Dickey's mostly picked the low hanging fruit - the K2 and the ghost box again - without taking the trouble to update himself and look at the way that the better informed, more sophisticated paranormal investigators operate these days. The items mentioned are really for the beginners and for entertainment. Although they may experiment with them, no paranormal investigators worth their salt use ghost boxes or K2 meters on investigations performed for clients. Dickey's opinions are not news to us: we already all know those things are trash.
Ghost boxes and similar devices based on the original Frank's Box, including phone apps designed to do the same sort of thing; that is, to throw up apparently random words that can appear to the over-enthusiastic, I-want-to-believe ghost hunter to be significant to their investigation. Whether this is achieved by sweeping the radio broadcast frequencies or using an array of memorised keywords is irrelevant: such devices are for entertainment, not paranormal investigation.
But a more sophisticated approach to paranormal investigation is not to use the various tools in the box to attempt to detect and record ghosts, but instead to gather information about the environment that is under investigation. A simple, compact camera, for example, is an excellent note taking tool for recording details of the environment at different times during an investigation - during the daytime, before the investigation proper, and throughout the night. The more photos from different sources, the better. The same can be said for video cameras, fixed or hand-held. Photographic evidence is general more useful for elimination of possibilities, for example, if movement of an object was caused by a person, accidentally or otherwise, rather than by, say, a poltergeist. Once, on a particularly creepy investigation, footage from our fixed cameras eliminated the possibility that an intruder caused a downstairs door to slam violently, as we'd first thought.
EMF meters? Well, we humans are (mostly) not sensitive to electro-magnetic radiation (except for heat, which we feel, and visible light) so the meters can tell us of something present that we can't otherwise detect with our own senses. An example: during one investigation, a resident said that when she went to the kitchen sink, it often felt like someone touched her hair and shoulders. Well, we noticed she wore house shoes with synthetic soles and we suspected she might be charging herself up with static electricity while walking on the carpet (causing her hair to rise and separate slightly) then earthing herself when touching the tap or steel sink bench, causing her hair to sink back and brush her shoulder and making her think it was being touched. Measuring around her with a Trifield Natural EM meter confirmed this. We measured ourselves as a comparison and the readings were much lower. Hypothesis confirmed, paranormal experience explained.
It is said that positive ions in the air can affect people's mood negatively, so the presence of positive ions in a particular room (perhaps caused by equipment such as a photocopier or printer) might make that room feel strange, somehow different. Well, one of these devices will detect ions, positive and negative, and give a rough count which then can be compared to other spaces. (Note: we don't yet have an air ion counter, but would love one and would put it to good use. But they're kinda expensive. Can anyone help?)
The same can be said for thermometers; ambient, laser (non contact) and heat cameras. 'It's cold in this room!' Well, how cold, exactly? 'I feel chilled?' Really? Physically, or is it more of a physiological reaction to fear? Thermometers are useful gadgets for paranormal investigation, as they give you readings, which can be compared to other readings.
The same could be said for other detectors, measuring tools and recording devices employed by paranormal investigators; and yes, they are all purloined from other fields of use, but they all help to understand an environment in which paranormal activity is purported to occur. And they all either give numbers and quantities to things we can sense and/or detect and record things beyond our ability to sense. This is all mainly useful for understanding the natural qualities of an environment that may be contributing to a sense that the paranormal is occurring. The equipment can also help to rule stuff out.
So, putting aside the purpose-built paranormal gadgets mentioned earlier, as well as phone apps, that are really all just for entertainment purposes, and to break the inevitable monotony of those paranormal investigations during which nothing paranormal occurs - that is; ninety-nine point something percent of them - the tools that serious, scientific-minded paranormal investigators use in their hobby or (for the lucky few) their profession, are not necessarily as daft as the article The Broken Technology of Ghost Hunting would have us believe. At least, in the right hands.