Measuring on-line tobacco rod basis weight using combined high accuracy/slow response and low accuracy/fast response gauges

A method for on-line determination of basis weight of a rod of material comprising the steps of:

• monitoring basis weight of a rod of material with a high accuracy low radiation beta gauge having a slow response time;
• maintaining a running average of basis weight determined by said low radiation beta gauge;
• monitoring basis weight of said rod of material with a low accuracy dielectric sensor having a fast response time;
• maintaining a running average of basis weight determined by said dielectric sensor;
• calculating a correction factor for said dielectric sensor based on said running averages;
• and
• applying said correction factor to said dielectric sensor to generate a fast response, high accuracy basis weight for said rod of material.

Apparatus for on-line determination of basis weight of a rod of material comprising:

• a low radiation beta gauge for generating a high accuracy, high response time basis weight signal;
• a dielectric sensor for generating a low accuracy, low response time basis weight signal;
• and
• a processor for combining said high accuracy, high response time basis weight signal and said low accuracy, low response time basis weight signal to generate a high accuracy, low response time basis weight signal.