Abstract: A network communication system includes a packet translator operatively connected between a tributary network port and a trunk network port. A tributary format is communicated through the tributary network ports and includes tributary packets that each include a header field and a data field. An aggregate format is communicated through the trunk network port, and includes a packet that includes an aggregate header field and the data fields.

Abstract: A method of calibrating polarimeter to work at an unknown wavelength comprising calibrating the polarimeter at a standard wavelength, using the calibrated polarimeter to measure a sample, measuring the same sample at the unknown wavelength and setting the polarimeter to give the same measurement at the said unknown wavelength as at the known wavelength. The method is particularly applicable to be calibration of a saccharimeter to work at an unknown wavelength in the near infra-red for the measurement of dark sugar samples. The invention is also a polarimeter or saccharimeter for carrying out the method.