It's the week after the Masters Tournament, and while the hangover from the season's first major is still lingering, golf is not stopping. The RBC Heritage, the PGA Tour's fifth Signature Event, is here, but so are important changes to the rules of the American-based circuit.It is true that these are not definitive changes, but tests that the PGA Tour is making as part of its efforts to accelerate the pace of play. However, these are drastic measures that, if generalized, will bring a completely new scenario to the tour.The first of the rules to be tested this week will allow the use of distance measuring devices, read rangefinders, by competitors at the RBC Heritage. The measure was announced last January and will be tested over six tournaments this spring.The use of rangefinders is nothing new in golf. They are commonplace in most women's tournaments, the DP World Tour and the PGA Tour Champions. The PGA of America allowed them in its championships, including the PGA Championship, starting back in 2021."The use of distance-measuring devices has been brought up, and I think that right now this particular rules committee is very accepting of that. It's been tested on the Korn Ferry (Tour) level. It's been tested for a full year at the PGA TOUR Champions level. Why not?" said about the subject PGA Tour Senior Vice President Rules & Competitions, Gary Young.According to Golf Digest, the rangefinders will be tested by the PGA Tour on fields of varying sizes. In addition to the RBC Heritage, they will be used at the Truist Championship, the Zurich Classic of New Orleans, the OneFlight Myrtle Beach Classic, the Byron Nelson and another event to be announced.As for the second rule being tested this week, it is a new penalty policy for slow-playing players. The measure will be tested at the LECOM Suncoast Classic, a part of the Korn Ferry Tour which begins Wednesday, April 16, at Lakewood National Golf Club in Florida.According to Golf Digest, the new policy will include a warning for players who engage in slow play. A second warning will include timing them and, if the problem persists, a penalty stroke. The previous policy included the same steps, but added a "freebie" before eventually carding the penalty stroke.Slow play has been in the spotlight for several months, not only on the PGA Tour, but in golf in general. The LPGA Tour recently implemented a new policy that includes penalty strokes and fines for players found to have this problem.Other measures implemented by the PGA Tour to address the problem include reducing membership and fields for most of its tournaments.More Golf: Sahith Theegala Reaction to Rory McIlroy's Masters Finish is Must See TV