EVM430-FR6047: Calibration, USS tool

Hi,

larry li said:

1) We use DN20 pipe, we need to achieve R400, the minimum flow point is 0.016 m3/h,

    using segmented fitting calibration, it is recommended to divide how many RANGE ？each section 5~10 points.

It usually depends on the pipe characters. You can first run the meter at different flow rates without calibration. When calculating the calibration parameters, it usually automatically grouped into different ranges In each range, they have similar calibration parameters.  

larry li said:

2) Each water meter, as long as it is calibrated once, a calibration table can be generated,

     or it needs to be calibrated many times repeatedly to produce stable and accurate calibration table

It usually only need calibrated once if there is no other issue on the calibration process.

larry li said:

3) In the calibration of USS, why does the VFR flow need to set the Error Threshold, but not the VRF flow+ Temperature?

Because the VFR Flow is a simple calibration method, and easy to know the error of each calibration point. If the error of this point is higher than the error threshold, it will reports an error. 

larry li said:

4) In the USS tool, there is no place to enter RANGE in VRF flow+ Temperature mode, in fact the RANGE is define by us , we manually segment the data and input it into measurements table,

    only no RANGE prompt, right?

Yes. No range in VFR flow + temperature method.

Best regards,

Cash Hao