How to maintain oil temperature when deep frying at home? I was frying chicken and I noticed the amount of time needed to fry the chicken and how dark the batter will end up depends largely on the temperature of the oil. 

The problem is, the oil temperature when it reaches equilibrium (or almost constant temperature) will vary depending on the amount of chicken inside, the volume of oil, and the heat outputted by the stove. For home cooking, this is a disaster and very variable way of cooking.

The only way I can think of becoming consistent is buying a thermometer that will constantly monitor the oil temperature. I had one where I had to place a meat thermometer on the oil and hold it just so it won't touch the metal portion of the pan, but this is tiring and the heat tends to go all the way up the thermometer--and to my hands and it gets too hot. It may also damage the thermometer this way.

Is there a more industrial (and heat resistant) but affordable thermometer where I can just leave it on top of the oil so I can adjust the heat element to achieve desired temperature for deep frying at home? If none, how to properly deep fry at home to get consistent results?
My meat thermometer can bear temperatures above deep frying ones so I just use that and I keep the tip "suspended" in the oil with the help of the pot's handle and the thermometer's own cable. 
An alarm at 170 Celsius helped me last time to keep the temp under control. For the record, I was frying this 
https://en.m.wikipedia.org/wiki/Struffoli

Since I don't deep fry more often than once a year, I can totally live with this solution.