When sourcing an automatic powder feeder, you must prioritize feeding accuracy (tolerance levels) and flow rate stability. Key specs include the feeding mechanism type (e.g., screw/auger, vibratory, or loss-in-weight), hopper capacity, and material compatibility. Ensure the contact parts are made of SUS304 or SUS316L stainless steel to prevent corrosion and contamination. Additionally, verify the motor type; stepper or servo motors are preferred for high-precision applications compared to standard AC motors.