It uses a Viglen 486 laptop computer with a Pico Technology analogue to digital converter unit. This allows 11 sensors and data is recorded using Picolog software. This equipment has been deployed at a number sites over the years. The problem is always that you need the ghost or poltergeist to cooperate and perform for you and the equipment. We have had many puzzling effects.
Computers seem much more prone to malfunction in some haunted houses.
For one investigation, I checked the computer at home, and it worked normally. At the haunted Hotel it could not be persuaded to produce anything sensible at all. On the very few occasions when we have obtained computer recordings of paranormal events, the results have not been sensible or consistent. The presence of electricity grid transformers, underground cables etc. Most people would not notice this, but some are very sensitive and will report an oppressive feel in the presence of strong fields.