NMi confirms Accuracy Class 0.5
All others are Class 1.0

A 4” and 8” being calibrated at low flows at the NMi calibration facility Bergum (The Netherlands)

V12 continues to break records
The Lintorf test results from October 2008 proved that the V12 is the first ultrasonic meter to have a short minimum straight length of only 5D and still comply with the ISO17089 standard.

In December 2008 the Dutch NMi concluded that the V12 is the first ultrasonic gas flow meter to have an accuracy class of 0.5 according to OIML R137-1.

All other ultrasonic flow meters so far have accuracy class 1.0. Moreover, in early February 2009 low-flow tests at the NMi test facility Bergum showed that the V12 has the lowest minimum flow rate at all diameters compared to products currently available on the market. In fact, the V12 continues measuring low flows where competitive products are out of CT limits.

To justify this 4” and 8” V12 were tested at lowest flows. The 8” was tested with a remarkable turn-down of 200:1, measuring 15m3/h within CT accuracy. The 4” even went down to 10m3/h. The flow rates are specified in the MID T10170 issued by the NMi.

The reason for the remarkable results is in the design of the chord configuration. Five horizontal paths in a V-shape - even in the small 4” meter - scan the flow profile better than any other ultrasonic meter. And the reflective design doubles the acoustic path length compared to direct-chord designs which gives the V12 higher accuracies since the transit time method produces better accuracy the longer the path is.