Inkjet printhead device, fluid ejection device, and method thereof

A fluid ejection device, comprising:

• a plurality of ejection chambers comprising nozzles and corresponding ejection members to selectively eject a fluid through the respective nozzles by forming a vapor bubble in an ejection chamber which forces a fluid drop out the corresponding nozzle, wherein:
• a first subset of the ejection chambers are test ejection chambers;
• a second subset of the ejection chambers are non-test ejection chambers;
• the test ejection chambers:
• have nozzles with diameters greater than diameters of nozzles of the non-test ejection chambers;
• and
• comprise a pressure sensor plate;
• and
• a number of pressure sensor units comprising at least one pressure sensor plate to output a voltage value corresponding to a cross-sectional area of an amount of fluid in at least one ejection chamber.

A fluid ejection device, comprising:

• a plurality of ejection chambers comprising nozzles and corresponding ejection members to selectively eject a fluid through the respective nozzles by forming a vapor bubble in an ejection chamber which forces a fluid drop out the corresponding nozzle;
• a pressure sensor plate coupled to an ejection chamber of the plurality of ejection chambers;
• a refill determination module to determine an amount of time to refill a number of ejection chambers;
• and
• a count determination module to determine a supply condition based on an output from the refill determination module.