The pilot program is part of a revised settlement over a deadly house explosion in South Philadelphia in 2019.
Two men were killed on South 8th Street and five homes were destroyed when a leaking gas pipe set off the blast.
One of the victims was 65-year-old Rudi Kambong, who was bedridden. The other victim was 28-year-old Brian Diu.
Viewer video: South Philadelphia explosion, fire leaves two people trapped
Philadelphia Gas Works previously told Action News the crack happened in a 6-inch cast iron gas main from 1928.
In 2021, the family of one of the victims filed a wrongful death lawsuit against the company.
PGW was accused of failing to maintain and replace its network of aging pipes.
The detector program is scheduled to launch within nine months.
PGW also agreed to seek a federal grant to modernize its natural gas distribution system.
The Pennsylvania Public Utility Commission unanimously approved the terms of the settlement.