iPhone Screenshots


Updated for iOS10.

Only Useful for Industrial Radiographers!

This is an application to replace the aggravating usage of slide rules to calculate radiography shot times.

It is applicable to Industrial Radiographers working with radioactive materials (not x-ray machines).

It works with both Iridium and Cobalt sources.

This app has been tested in the field with working radiography crews and the response has be great.

Just set the number of curies, the thickness of the steel (inches), and the source to film distance (in inches). Hit the calculate button and you will have the exposure time.

What’s New

Version 4.0

Fixed crashing issue in iOS 10.

Ratings and Reviews

Raistlinsly1 ,


This app works very well just like using a slide calculator

Val0010101 ,

What R Factor are y'all using?

I'm using Agfa D5 and shooting for 2.5 density the r-factor I have is 2.7 . So what r-factor would y'all use and how did you get it? The formula I normally use is: 1st step ( wt + wt + weld build up) gives you total thickness of steel, align the total up with a chart and that gives you the energy of IR192. 2nd step ((pdi*pdi*eIR192*RF)/(Curies*1000)) basic algebra and wala. I always come up with two different shot times using the formula vs. the app, (app 45-60 seconds longer). I know the formula is right, been using it for years. So why isn't it working for me? The Barricade app is great, sure beats using the inverse square law. But don't get to dependent on it bc you cant use it tests.

chesspupil ,

Great TechOps and Amersham Match

I compared the time results of Ir-192 to what the techops and Amersham slide rules use and I get the same results or very close. Now I would like to see for materials other than steel, and perhaps an option to choose a density and a film type and it give you a probable R-factor. (Developer temps would then be needed)

One complaint is that I need to hit the numbers key every time to switch over from alphabet to numbers for every entry. (Curies, SFD, R-Factor) I have seen other apps get around this.


Lance Henderson
335.9 KB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 2009 - 2016 Lance D. Henderson


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