What is the Best Tool to Measure Cartridge Azimuth?

What do you use to measure / set azimuth of your cartridges and / or styli? I am afflicted with diminished eyesight, so aligning the azimuth of the stylus by eye is not practical.

To that end, I’ve use a simple bubble level (spirit level) about 1-1/2” in diameter to get the headshell as close to level as possible, after first leveling the platter by adjusting the turntable feet. 

I figure some clever lever engineer has made an easy to use electronic tool for this purpose, but I haven’t found anything in my searches. Nature abhors a vacuum, so one day if not already, it might surface. 

Until then, does anyone have alternate methods? How about using a test record? Is that feasible? I do have a couple of good oscilloscopes by the way, so I can make precise measurements of levels, phasing, frequency, etc.... 
I have a few test records in my collection, so I’ll have to check if any have the single channel 1kHz tones. I couldn’t imagine not having at least one good oscilloscope. For a long time it was a 20mHz Philips 2 channel with CRT, but I have a Tek 100mHz 2 channel with LCD screen also now.  Also have 2 Technics TPBGA003 headshells on order (C$120 each from Panasonic through my Technics / Panasonic dealer) that have the azimuth adjustment feature. The guy there tried to convince me that everything from the cartridge and turntable factories is already optimally aligned, but I want that extra degree of certainty. 
Great minds think alike. I should think a USB microscope would work fabulously well. I use 10X loops because I already have them. You can get a USB microscope for much less!
For those who are using a mirror make sure you have one that is slivered on the same surface as you rest the stylus, or you will set it wrong.  ( you can get the proper mirror from a camera repair)