Checking rig tensioning based on frequency

[Viviane2000]

So in a couple of days we will have our rigging checked and the tension will be adjusted to the correct amount. I've read that you can check the tension of your timing belt based on frequency. Now I'm wondering if I can do the same for my rig?

When the rigger is done and my rig has the correct tension, can I use a mobile phone app to find the frequency of my rig. I'll make notes of the frequency of different parts of the rig.

In a year time I can check the frequency of my rig then vs the frequency in my notes - that should give the correct rig tension? What are your thoughts? Am I missing something? I'll also write the temperature while noting the frequency, I'm guessing temperature will impact frequency?

[Yngmar]

I tried this. You can't. The resonant frequency of our shrouds at full tension was too low to detect with a phone microphone. No surprise, it's a much longer span than the average contrabass 

You'd have to find some other way to measure the frequency, or use the stretch or deflection methods. Some riggers use a deflection gauge to measure tension, Selden documents the wire stretch method in their "Tips and Advice" book on how to tension it yourself. Most riggers go by feel, some actually go sail the boat.

[Viviane2000]

Ah, shit. When things sound too good to be true..

[Jake]

A proper rigging tension gauge is not that expensive.  Loos makes one for wire rope and another for rod rigging.  They are the best method of setting rig tension.  Racers use them all the time for repeatable settings, depending on the wind strength.

Jake
2004 Bav 44