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.... 
128x128sleepwalker65
The Fozgometer ostensibly could be replaced with a decent oscilloscope, so what is it’s benefit to someone who already owns a couple of high-end oscilloscopes? Don’t take my question as being combative, I’m just curious if the Fozgometer has any unique qualities that lend it to being better or easier to use for the task. 
The most accurate way is an oscilloscope. Using a Fozgometer is second. My problem with it is the price. Both methods align the coils with the record not the stylus. If there is one manufacturing inconsistency that worries me most is the stylus not being properly aligned with the coils, an easy error to make. The above methods may result in the best sound but I prefer the least record wear so I use the mirror method lewm referred to above. That gives you a stylus aligned to the groove and you can't beat the price. I do add loops to the process.

Mike    
I am in agreement with those who prefer that the stylus be properly aligned to the groove over a correct electrical alignment.  With my current setup, I used the mirror approach to get a decent visual alignment of the stylus to the groove.  I then used a Fozgometer which indicated such a small change that there was hardly any change to the visual alignment (good for me that the cartridge was built so well).
I use a now ancient Signet Cartridge Analyzer along with its companion test LP made by Shure.  The SCA has a ‘scope output, but if you have no scope, it has a dB meter built onto the faceplate.  So, play test LP with (usually) 1kHz test tone in one channel only, set the signal appearing in the driven channel to 0 dB, and measure dB of output in the opposite channel, shown on the meter as a negative number of dB.  Then play the band with a 1kHz test tone only in the opposite channel and likewise measure the output in -dB that appears in the non-driven channel on the meter (or on your scope).  Alter azimuth from 90 degrees to get the least crosstalk, L to R vs R to L.  In my experience, it is folly to try to achieve exactly equal crosstalk levels, R to L and L to R.  Best to just go for the best absolute values.
By the way, I agree that there is no need for a Foz if you have an oscilloscope and know how to use it (which many don’t). You still do need the test LP with 1kHz signal in one channel only. (Needs two bands, one for L channel only and one for R channel only.). Shure made such an LP for the Signet Cartridge Analyzer, for one example. And I agree that in the end it may be best to just adjust the stylus so it sits properly in the groove, regardless of crosstalk, in which case you are relying upon the manufacturer to have built the cartridge to exacting standards, which some do.  99% of the time, I adopt the latter leap of faith.  I think the obsession with azimuth may lead to more alignment errors and more distortion and stylus wear than one would care to admit.