I used to have a glow bee. You had to hold it about 2" away to get a steady reding, even in sunlight.

So one day I was in front of the engine trying to get a reading when the engine tore up the motor mount and tore the eye off the end of the glow bee. I will ever be thankful for it saved my hand. But come to think of it if I didn't have a glow bee, i wouldn't have had my hand there.

The moral to this story is:
I bought a TNC and take all my readings from behind the prop.

enjoy

jim