BIZERBA
letter scale

Bizerba letter scale

This nine! kilos heavy letter scale was not intended for domestic use but was intended for use in German post offices and for use in mail rooms of larger companies. This letter scale has a long history and is shown in catalogs of 1936. According to Rübenthal it was already provisionally accepted for calibration on February 20, 1933. On pp. 2808-2810 of the Dutch journal Meten & Wegen, of June 2002 no.118 R.J. Kok described an article with the titel Een oude brievenweger in moderne uitvoering this Bizerba letter scale and an English predecessor from 1840. The letter scale weighs in seven weight classes like the German Mail and has seven separate counterweights, the rolls. Per weight class a roll is picked up by the arm of the scale, when a weight limit is exceeded the next counterweight is picked up. Above 2000 grams the movement is halted by a rubber stop. The photographs illustrate this. The weighing motion is damped by a damper filled with silicone oil. The scale has a distinctive ticking metal sound with changing tones: the rolls make themselves heard ar pick up and put down. This letter scale has a spirit level

back of the Bizerba letter scale

to help leveling this scale with three adjusting feet. To prevent leakage of oil out of the damper during transport the damper has a sealing nut to be moved and then tightened. The damper and nut are located behind a removable panel on the side of the scale. The weighing platform is fixed with two screws on a robust aluminum casting. In the cavity of the casting are the lead particles used for the fine adjustment of the scale. The letter scale has a lead strip on the base plate. Herein, the verification or approval marks were made. This copy bears a 1985 mark. Later approval was marked with round stickers on the scale house. The letter scale was sealed with a cable through the heads of the two screws on the spirit level side of the scale and the cable was secured with a lead seal, they are not visible in the pictures here. With this letter scale design it is cumbersome and awkward to change the postal rates table when needed. The seal must be broken to reach the inside of the house and release the postal tables from the glass plates and install newer tables. The pivots are robust knife-edge bearings. The scale has rubber stops at the beginning and at the end of the movement of the scale arm. The trade name Bizerba comes from the founder of the factory Andreas Bizer from Balingen. Below some more pictures of this Bizerba letter scale.

animation: [move the pointer over the photo] Unloaded scale and scale loaded with 1000 grams

animation: [move the pointer over the photo] with and without a load between 250 and 500 grams

dismantled scale house, mechanism at rest	the seven counterweight rolls	loaded above 2000 grams, the scale arm presses against the rubber end stop
two adjusting feet at the scale side of the spirit level	the third adjusting foot is placed at the scale side near the oil damper	the oil damper and the sealing nut resting on top of a spring clip
the weight of the mail item is between the indicated values	a robust knife-edge bearing	at top and bottom a rubber end stopper
the function	the company name	gauging office- and year-mark in the lead next to the spirit level
the damper is situated at this side of the letter scale	the removable panel with instructions how to close the oil damper for leakproof transport	the panel removed the oil damper rod with nut and clamping spring are within reach
nameplate with the lead of the gauging office scale production year and month: August 1982	the lead particles of the fine-tuning	the seven counterweight rolls

the postal rates are in Pfennig, that is the subdivision of the German currency Mark. abroad, the GDR with East Berlin and the Federal area, inland in West Berlin and 4 or 6 postal categories for the seven weight classes. the standard rates are bold rimmed. these rates were valid from July 1, 1982 until April 1, 1989.

on the other side are the postal rates for domestic and mail abroad of letters and small packages with different dimensions the white patches are stickers with recent changes not authorized weights for each category are the dark areas