We manufacture a conveyor belt type product that is endless. We have found that the measuring tapes that we use are catagorized as "ECII", which means that they have more tolerance than our process can tolerate. On top of that, the manufacturer is not ISO certified.

From what I have read, there are 3 types of tapes...ECIII, ECII and ECI...like a good, better, best grading, with each "grade" having an acceptable tolerance.

I am looking for recommendations and advice on purchasing the most accurate and repeatable (tape to tape) steel tape measures in lengths of 30 meters, 50 meters and 100 meters. My only requirement would be that they should have a "certificate of accuracy" or "certificate of compliance" with each tape.

From what I have read, there are 3 types of tapes...ECIII, ECII and ECI...like a good, better, best grading, with each "grade" having an acceptable tolerance.

I am looking for recommendations and advice on purchasing the most accurate and repeatable (tape to tape) steel tape measures in lengths of 30 meters, 50 meters and 100 meters. My only requirement would be that they should have a "certificate of accuracy" or "certificate of compliance" with each tape.

Normally, only tapes used in surveying works comes with certificates and may be calibrated periodically and comes with the 'EC' marking. The usual temperature, tension and sag correction applies. These tapes comes in some fixed lengths and may be joined and usually need to be supported at these joints to control the effect of self weight or sag. Have a look at the following site for details of ECI,II & III. www.yorksurvey.co.uk/tipstrik/tips23.htm

In US, perhaps you can try 'Starret'. Also, why not consider the electronic type (EDM) - I think they are more practical and user friendly. Whether the manufacturer has ISO is not important but the calibration certificate is key.