Up till now, Carney funnels have not been calibrated for testing flow rates, but instead have only been supplied for testing the apparent density of non-free flowing metal powders.
However, the committee has now approved a standard calibration powder to be used to calibrate the funnels, says Kymera International, which can reportedly supply the powder.
According to the company, the calibration powder is a 316L stainless steel screen cut that has been tested for stability and repeatability of flow time over an extended period of drying and testing. In a master Carney flowmeter funnel used by Kymera, the flow time for 150g of the calibration powder to flow through the master funnel was 31 seconds.
The MPPA Standards Committee will be coordinating an interlaboratory test program in 2022 in conjunction with ASTM Committee B09 on Metal Powders and Metal Powder Products to determine the precision of the Carney flow rate test method, Kymera said.
