BoxRec

got 'Salter' scales at home, but just started back down the gym, and their electronic scales show me 5lbs over the Salter scales.

I don't know, TBH. However, bear in mind that digital (electronic) scales will only be as accurate as the analogue to digital converter contained within them allows.

Usually you get weighed in with the nearest ones handy. At championship weigh ins proper calibrated ones are used, but undercard fighters don´t tend to be there at the official weigh ins.
That is normally done by their local board member or sometimes at the venue itself. In these cases all sorts of scales are used, often crappy bathroom ones

The promoter normally supplies the scales (or should a say Dear Mr Goodhall,bring's em with him) these are normally very accurate,
as im often informed to keep my eye on them,cos they was £300,,,Ok Mike,point taken!!!!

Oh dont talk to me about scales. My mum is always weighing herself.

Get yourself a set of Hanson HX6000 scales, they are black, glass, ultra thin and look the dog's bollocks. My missus just got some for the bathroom