Printer fluid impedance sensing in a printhead

In some examples, a printhead includes a firing chamber to receive printer fluid, an ejector positioned in the firing chamber to eject printer fluid droplets from the printhead, and a nozzle in fluid communication with the firing chamber. The printhead can further include an impedance sensor positioned in the firing chamber to contact printer fluid to measure impedance values of the printer fluid. The impedance sensor can be connectable to a controller to transmit impedance values of printer fluid to the controller. 在些示例中，打印头包括：喷发腔室，所述喷发腔室用以接收打印机流体；喷射器，所述喷射器定位在所述喷发腔室中以从所述打印头喷射打印机流体微滴；以及喷嘴，所述喷嘴与所述喷发腔室流体连通。打印头还可以包括阻抗传感器，所述阻抗传感器定位在所述喷发腔室中以接触打印机流体从而测量所述打印机流体的阻抗值。所述阻抗传感器可以是能够连接到控制器的以将打印机流体的阻抗值传输到所述控制器。