What Emissivity level is used on Brontx connectios

I'm assuming you meant Bronze?

According to the table here...
http://infrared-thermography.com/material.htm
... it is approx 0.1 when polished and 0.55 when rough (for the frequency band of long-wave cameras, which is most these days)

I usually try to avoid estimating temperature from low emissivity metal surfaces and if possible focus my attention either on insulated conductor nearby or cavities in the piece which will move the effective emissivity much higher.

If it is bronze or some other known material you can use tables to estimate the emissivity (chances are there’s one in the back of your camera manual), but if you need a precise measurement you'll need to make an emissivity test of some form.

This is particularly important with metals or other low-emissivity targets, as the lower the emissivity becomes the larger error will be involved in your estimation.

A method taught to me was to apply electrical tape to part of the target (when its switched off!) as this has a standard emissivity you can use to make a comparison (generally around 0.9). Turn your target on or heat it up to about 20 degrees C above ambient, and use the comparison of the tape temperature with the target temperature to work out the required emissivity.

It may be possible to measure actual emissvities of materials like bronze but changes are very good the value will not be accurate nor will the correction it provides. If you can control ALL other variables and if the target is quite warm, accuracy may be acceptable but in the real world it is not very productive. I would strongly suggest you add a high emissivity target, such as electrical tape or Glyptol paint or whatever your procedures allow, and work with that; your results then be very reliable (plus or minus 2%).