IF this a one of repair, just take the wheel to your LBS, or maybe a bike Co-op if you have one near.
IF you have a good ear, you can tune by tone by twanging.
There are musical charts on the web that show what note a certain length spoke should sound like at a certain tension.
IF all the spokes have the same pitch when "twanged", the tension is even.
That absolutely doesn't work for me. Either my Asperger's or one of my attention disorders gets in the way. I tell that 2 spokes have a different tone, but I can't tell which is which unless one is a "thunk". Weird and frustrating!!!! "Thunks" are spokes that you can wiggle.
I have the PARK tension meter. I've never had it calibrated, but I found it very useful in my early years.
I simply didn't have the :connection/feel/oneness with the wheel.
Once you start doing wheels on a regular basis, you'll "need" it less & less.
If the similar to PARK meters are noticeably less money, I'd probably go that way.
It's more about having all the spokes one one side with EVEN tension then a specific number.
You can always compare the sound of your "twang" vs a professionally done "twang" and adjust.