This is apparently a reliable and qualified Lab, specialized on TL tests.
I do not know if they are reliable within other areas, but for sure they are not on ancient Chinese Ceramic
Ware, at least by looking at the many, obvious false authentication that can be often seen on Katawiki, authenticating the many fake items sold by the same, shameful British seller Pax Romana.
Beware.
What many can't do good,Kotalla can.
Most professional and trustworthy lab i know by experience. Nummber 1 in the world