Mettler K7T

My other laboratory scales and balances: Mettler B5, Mettler P1210, Sauter L10

I recently obtained this Mettler K7T laboratory scale from the late 1950s to early 1960s. It has a resolution of 100mg with a capacity of 800g.

Mettler K7T


The internal mirror was fairly dirty, so I gave it a clean with isopropanol.


The case didn’t actually have any normal rust spots, this looks more like some corrosive chemical spilled onto there at some point. I cleaned the surface rust off and applied a layer of Ballistol, to prevent new rust. I also removed the cellular tape remains with brake cleaner.

As with all my mechanical Mettler balances so far, this one uses a B15S 6V lamp as well and mine also had a replacement bulb in the case.

Mettler K7T post cleaning


Using my cheap OIML M2 weight set. I did not calibrate the balance, just tared it to zero.

Read Nominal Weight Displayed Weight Deviation abs(Δ)1)
10g 10g 10g -
20g 20g 19,8g 0,2g
50g 50g 49,2g 0,8g
100g 100g 100g -
200g 200g 198,6 1,4g
500g 500g 500g -

1) Deviation is the deviation between the nominal weight and the actually displayed weight