Ghost hunting has become a television sensation, with help from an unexpected accessory: the portable weather meter.

Years ago, weather stations were static installations, but these days all the necessary instrumentation can be packed into an electronic device no larger than a smartphone, providing a handy scientific device for meteorologists – and for spirit seekers.

Paranormal investigators associate cold spots or sudden drops in temperature with the presence of ghosts, and have long used wind chimes to detect drafts supposedly generated by spirits. Modern ghost hunters use devices such as the handheld Kestrel 3500NV, which measures temperature, pressure, relative humidity and wind speed. There is even a backlight for night-time use.

Tea Krulos, the author of a book called Monster Hunters, lists a portable weather meter as standard gear for paranormal investigators. Unlike dowsing rods or other traditional tools, these sensors provide objective, numerical evidence of what is happening at a supposedly haunted spot, rather than a vague, subjective sensation.

Cynics may say that toting a scientific gadget allows the investigator to give their claims a gloss of scientific credibility, while their audience may be inclined to consider the device in their hands as a spectre detector rather than a mere weather meter.