A flow cell and flow cytometer in which a nozzle at the end of a flow channel is disposed on a removable substrate held at a registered location on a flow cell. The mounting assembly including a stress-distribution member that has an abutment surface abutting a flange of the connector. A diffusion barrier is formed on a surface of the metal line forming region of the insulation layer. The risk criteria include one or more risk calculating and weighting factors. The output power is detected by detecting the absolute values of the voltage and current at the output of the amplifier and mixing the detected voltage and current to generate a signal related to the output power.