xdjdx

4 minutes ago, vlaiv said:

I don't think it has to do with individual photons energy, but rather their wavelength. Longer the wavelength, less chance to interact with matter. It is actually mismatch between wavelength of particle and atomic structure of the matter. So both long wavelengths go thru (like radio waves / microwaves), but also x-rays and gamma - very short, so cross section is small.

Anyway it can be easily checked. Do google search for "Is plastic IR transparent", and "Is plastic UV transparent". Results should give you some hints which is more likely culprit.

Looks like both. 

39 minutes ago, vlaiv said:

Plastic cover does indeed remove all visible light, but IR might get thru it. Since the mono version does not have IR protection window, it is a good thing to protect it otherwise, like using aluminum foil, or something else that is opaque in IR part of the spectrum.

I usually take my darks by placing camera "face down" on wooden desk (covered with plastic cap of course), and have not had issues with dark calibration.

Hello vlaiv

Would it be more likely to be UV as this is the more powerful wavelength. 

Thanks Olly. 

I have informed Sam at ZWO, as the poor man has had to put up with my questions about the 174 Amp Glow. 

I have just become the proud owner of a 1600 MM pro, and that has had the same cover (different foil)

It appears to me that just using the plastic cover does not prevent light leaks completely, and this maybe why people struggle with Amp Glow removal. 

Hello Mickey

I have an ASI174MM cool, I was unable to remove the Amp Glow, I discovered that covering the sensor with the supplied plastic cap, and then, covering the sensor end of the camera up to the vent fins with four layers of Aluminium kitchen foil, held in place with an elastic band. The amp glow calibrates out with the darks produced.