One ad hoc technique sometimes used during acceptance testing is to attach an encoder and chart recorder to the motor or drive shaft, and a trigger signal to the safety device used to initiate the stop. This procedure can yield precise velocity and distance data, but it is an invasive technique requiring substantial time and effort to set up. Consequently, it is never performed as part of a routine inspection process. In truth, the lack of appropriate measurement tools has hindered the industry's ability to know just how effective or safe a given escalator's braking system is. It is a noninvasive, portable field calibration system that measures and records speed and stopping distance, and compares those results with the appropriate safety code standards.
Test data is recorded in an accompanying laptop personal computer.
The program includes a versatile database to track and manage escalator owners, locations, units tested and test results, along with standardized inspection checklists. Jurisdiction-specific checklists can also be added. A U.S. patent application is currently pending. In some cases, tests were witnessed by in-house maintenance personnel, in some cases by the service contractor, and in other cases by the local inspection authority. One third of the units tested were installed after the adoption of ASME A17.1a-1991, which imposes the maximum deceleration rule.