NOHD Calculator

What is the NOHD (or N.O.H.D.)?

NOHD is the abbreviation of "Nominal Ocular Hazard Distance". It specifies the distance from the laser source source at which the intensity of a single laser beam becomes safe by not exceeding the MPE (Maximum Permissible Exposure) any more. The laser beam is considered to be dangerous if viewed from a closer distance than that.  

THIS TOOL IS NOT SUITABLE FOR CALCULATING THE SAFETY OF A LASER SHOW DISPLAY! IN SHOW LASER INDUSTRY IT IS ONLY RELEVANT FOR DETERMINING THE SAFETY DISTANCE FOR OUTDOOR LASER DISPLAYS WITH SINGLE BEAMS, WHICH IS A VERY RARE OCCASION, AS THE BEAMS ARE USUALLY DEFLECTED AND MODULATED IN OUR INDUSTRY!

Laser shows with deflected and modulated laser sources are considered safe at very much closer distances, usually only several meters!

Like the MPE, the NOHD depends on several parameters :
  • The output power of the laser
  • The beam specifications diameter at aperture and divergence
Under certain circumstances special optical instruments may be used for viewing the laser from farer distance. This fact must be considered when determining the NOHD. This calculator does not repect any optical instruments at all, as it's highly unlikely that this needs to be considered in shol laser industry. However, it's up to the operator's respondibility to do a proper safety risk assessment.

This NOHD online calculator is provided as is. Laserworld cannot be held liable for the results nor do we guarantee the correctness and accuracy of the results. The NODH calculator is only applicable for laser sources in cw operation mode and only valid for the wavelength span from 400 to 700nm - which are common parameters for show laser systems.


Please fill in all values, otherwise the NOHD cannot be calculated properly
Laser specifications:
Power [mW]:
Divergence [mrad]:
Diameter at aperture [mm]:

Decimal separator is: . (Point), not Comma

The NOHD distance is:



What do I need the NOHD calculation for?

The NOHD value depends on the characteristics of the laser systems used. In show laser industry this value can be requested by authorities to determine potential risks for aviation. As there are pretty high power laser systems in the market, and as they are very accurate as well, these lasers can reach over very long distances. Even though the MPE values are extremely low for what human eye could actually stand in terms of immission of optical radiation, some authorities require the NOHD.
The calculator above can help you in determining this Nominal Ocular Hazard Distance with ease. Be aware that the divergence heavily influences on the actual power over distance.
e-max.it: your social media marketing partner

Distributed brands:

logo-laserworldlogo-swisslasHB-Laserlogo-ray-technologies-rti
logo tarm
logo-pangolinlogo-coherentlogo-wireless-solutionsint visionsSpider-Laser-Game

logo-vplt-foerderndes-mitgliedilda logo black cleanedup 2006 member


Contact us:
ch +41-71-6778080
en +44-161-8188969

 

You agree to the disclaimer of this page with using it.