Quality control within the factory


Especially in the early company history, new products and their functionalities are designed and developed intensively together with the customer, sales and development.
Production and quality assurance are involved right from the start of a new development in order to be able to manufacture products that are suitable for production and testing at quality insurance department.

This is the only way to guarantee a high standard of quality assurance.

As is still common today, a plate mentioning the product type and a serial number for
sales control and tracking is produced for every device produced and attached to the
device during the manufacturing process.

The product data (type, serial number, etc.) of the devices to be delivered are entered manually in notebooks (device logbook numbers)

Here are sample pages from the years 1951/54 and 1973.


Pages from Geraetestammnummern Buch No1 1951 1954a

Device log book

1951  to 1954

Pages from Geraetestammnummern Buch No1 1951 1954a

Device log book
1973 no. 2


Further details on the manufacture of the nameplate:
• The design office (KB) and the development department determine which unit received
  a nameplate and where it should be attached. The nameplate is part of the parts list.
• The sales department starts a production order and determines the number of units
  to be produced.
• Order processing in production triggers the purchase of material and starts in-house
• If the parts list requires a nameplate, the device clerk gets the device numbers from
  the production drawing.
  (See the notebooks)
• Production has its own engraving machine for the production of the nameplates.
• When installing the device, the type plates are attached to the device / group by the
  fitter with grooved nails.
• Quality assurance (QA; at that time still "test field") had nothing to do with this process.

Later the device nameplates were made from thin aluminum foils with the Hell specific  layout on the front and an adhesive layer on the back. The device number was entered  within the specified field with a special thermal printer.

These notebooks are the only records of the:
devices produced, the production period and the production quantities.
  An overview of the three systems of serial numbers   (German)