Intercomparison on Water/Heat meters at 50 °C, 6-25 l/h

Project Description

The meter package consists of two meters; one Mag-meter and one Coriolis-meter.
This proposal is initiated by the common wish of the four laboratories to compare their calibration results in reference to a well established pair of meters. The meters have been frequently used for international assessement visits at several test facilities for hot water and heat meters in Europe. As there is no financial support for this project is not planned as a usual round robin. Instead the calibrations should be performed at occasions when the participating laboratories are visited by the pilot for other reasons. Due to the sensitivity of the meters and the value of their long calibration history, the pilot wishes to transport and be present at least when mounting and dismounting the meters and also to receive preliminary data on site. The allowed time for a calibration is maximum two days.

The meter package consists of a Mag-meter followed of a Coriolis-meter working in the flow range 6-25 l/h.

Proposed test points are 6, 12 and 25 l/h.

The number of pilot measurements at SP will depend on the final travelling scheme, but at least 2 measurements are planned.
No instructions are given in advance. The pilot plans to provide necessary information on site. A traditional evaluation will be performed and a draft distributed before finalizing the report.
A time schedule cannot be given, but the pilot expects the exercise to be finished latest in December 2006.

[28-10-2005] The project was proposed by the subgroup for water at the EUROMET meeting in March 2005.
The meters will be transported by car between the participating laboratories.

Final Report 2010-01-30

The comparison has been completed and the final report can be downloaded here>>

A calibration intercomparison was performed on flow/heat meters at three flow rates 6, 12 and 25 L/h at 50 ˚C. A package consisting of a Danfoss coriolis meter and an Endress & Hausser magnetic inductive meter formed the transfer package. The comparison was organized to simulate as much as possible a routine calibration situation. Considering the difficulty to measure such low flow rates at elevated temperatures a good agreement could be stated. Of totally 70 measurement points three were outside a ±0,2 % interval from the corresponding reference value and are considered to be outliers. But no systematic deviation was recognized. Two of the participants had no CMC-claims for water flow covering these low flow rates and this temperature. Thus no validation was possible. But for all laboratories the outcome indicates a calibration capability between 0,15 and 0,25 %.

Flow (F)
Krister Stolt, SP (Sweden)
Coordinating Institute
RISE (Sweden)