A full body scanner is being introduced at the Delhi airport on an experimental basis, CISF DG OP Singh said on Wednesday. Since the move is part of a trial exercise, it will be completely voluntary for now.

Unlike metal detectors, full-body scanners can see an outline of the passenger’s body, under people’s clothing. They can even detect non-metal objects such as plastic explosives as well.

This is not the first time that such an operation is being executed. In a similar experiment done five years ago, four full-body scanners had been installed at the Indira Gandhi International Airport. The decision was taken after the January 2011 bombing in Moscow but the experiment in Delhi was not successful.

The final decision on whether to use the scanners will be made after over a month when 10,000 people have been scanned. A 3-4 member committee will be taking the final call about whether these are required at airports. As per reports, the machine has the capacity to handle around 250-300 passengers in an hour.

In Western countries, the scanners have a computer program which prevents them from saving images that are being seen on the screen during the surveillance. Also, the person the full body scan cannot see the face of the passenger.

While security and intelligence agencies in India have been insisting on introducing such scanners, the Central government has been avoiding taking a call on them to avoid any controversy.