The Laser Safety Calculation Guide (PDF) has been developed to provide an overview of how to perform the MPE, NOHD and NHZ calculations for lasers and laser systems used at the University of Chicago to assist the user in laser hazard evaluations.

Maximum Permissible Exposure (MPE) One of the most useful values in laser safety calculations is the Maximum Permissible Exposure (MPE). This is the irradiance or radiant exposure that may be incident upon the eye (or the skin) without causing an adverse biological affect.

Maximum Permissible Exposure (MPE) can be thought of as a person’s laser safety speed limit . It is the maximum level of laser radiation the human eye or skin can be exposed to without hazardous effects or biological changes.

Laser radiation safety is the safe design, use and implementation of lasers to minimize the risk of laser accidents, especially those involving eye injuries. Since even relatively small amounts of laser light can lead to permanent eye injuries, the sale and usage of lasers is typically subject to government regulations.

An MPE is the level of laser exposure to which the eye or (less limiting) the skin, may be exposed without adverse affects. NHZ is the space within which the level of direct, reflected or scattered radiation during operation exceeds the applicable MPE.

Overview of laser MPEs These charts show the eye MPEs for various wavelength ranges. They may not include the changes made in the 2014 version of the ANSI Z136.1 standard. But these should be good enough to give a broad overview.

The Evaluator is based on the ANSI Z136.1 American National Standard for Safe Use of Lasers and will perform repeated calculations of maximum permissible exposure (MPE), optical density (OD), nominal ocular hazard distance (NOHD), nominal …

Maximum Permissible Exposure (MPE). This is the minimum irradiance or radiant exposure that may be incident upon the eye (or the ski. ) without causing biological damage. The MPE is related to the AEL by the limiting aperture of the eye, which is itself a func.

What is the MPE for accidental ocular exposure for a pulsed argon ion laser which emits 10 pulses per second at 488nm with a pulse duration of 1ms? Calculate MPEsingle. Calculate MPEtrain. We need to know the number of pulses, N, in the duration time, 0.25s. For 10 pulse per second this equals 2.5.

What are the laser MPEs? At the center of all laser safety guidelines and programs is the concept of Maximum Permissible Exposure (MPE). This is defined as " the level of laser radiation to which an unprotected person may be exposed without adverse biological changes in the eye or skin."