Coriolis mass flowmeter with no risk of metal ion elution

A Coriolis mass flowmeter comprising

• a straight tube through which a fluid to be measured flows;
• a vibration exciter for exciting the tube to vibrate;
• first and second vibration detectors for detecting the vibration of the tube;
• and
• supports for supporting each end of the tube to serve as fixed ends for the vibration;
• wherein the vibration exciter and the first and second vibration detectors are supported by a frame connected to the supports;
• wherein a mass flow rate of the fluid flowing through the tube is determined based on a phase shift of vibration waveforms detected by the first and second vibration detectors;
• wherein the tube, the supports and the frame are made of a carbon fiber reinforced fluororesin;
• wherein when M=Mt+m+Mf is established, m3 is larger than a total mass of m1 and m2, and m is not more than 0.4M when the ratio of m3/(m1+m2) equals 1, and m is not more than 0.6M when the ratio of m3/(m1+m2) equals 2, and m is not more than 0.8M when the ratio of m3/(m1+m2) equals 3, wherein the first vibration detector has a mass m1, the second vibration detector has a mass m2, the vibration exciter has a mass m3, m is a total mass of m1 and m2 and m3, the tube has a mass Mt, and the fluid flowing the tube has a mass Mf.