Interpreters always work in pairs and take turns about every 20-30 minutes, due to the required significant level of concentration, the ability to cope with different pace and different accents of the speakers.

A block is any translation that takes up to 4 hours. An interpreter’s full working day comprises two blocks, i.e. interpreting that lasts for up to 8 hours.

A certified translation page is a statutory page provided for in the Regulation of the Minister of Justice of 24 January 2005 on the remuneration for sworn translators and interpreters.  

You can send a scan of the document, but then the translator in the certification at the end of the translation shall write that the translation was made based on a scan of the document. However, many institutions or offices usually require a translation based on the original document.