Alternatives to Detecting Flame with IR Sensor in Daylight

Are there any other good, reliable ways to detect a flame in a propane burner? My design uses an IR flame sensor but I get way too many false positives in daylight outdoors. I've thought about a thermocouple but they can't withstand the heat. Anybody have experience with the gas sensors?

Thanks

Describe your IR flame sensor.

AFAIK gas cookers use thermocouples for flame failure detection.

...R

They have high temperature thermocouples. Omega makes thermocouples that can go as high as 1700 C. A perfectly adjusted propane - air flame can be slightly higher than this (~1900C) at the hot spot of the flame, but if you need a flame that hot, you won't be putting the thermocouple in the hot spot, right? Put the tc a quarter inch or so away from the flame. that way it won't interfere, PLUS it will be considerably cooler.