Fluid sense circuit with variable sensitivity

An ejection head comprising:

• fluid ejectors, and a fluid detection circuit electrically connected to at least one of the fluid ejectors, the fluid detection circuit configured to detect and characterize a fluid in the fluid ejector, wherein the fluid detection circuit is controlled by adjusting an applied voltage to the fluid detection circuit to change a reference current, thereby enabling the fluid detection circuit to detect fluids of different characteristic resistivity, and further wherein the fluid detection circuit is configured to exhibit a disproportionate bias voltage and reference current.

A method for dispensing a fluid with a fluid dispensing system, comprising:

• providing the fluid in a fluid reservoir, receiving the fluid from the fluid reservoir with a flow channel, receiving the fluid from the flow channel with an ejection chamber, using a fluid detection circuit to detect and characterize any of the fluid disposed between the flow channel and the ejection chamber, wherein the fluid detection circuit is controlled by adjusting an applied voltage to the fluid detection circuit to change a reference current, thereby enabling the fluid detection circuit to detect fluids of different characteristic resistivity, wherein the fluid detection circuit is configured to exhibit a disproportionate bias voltage and reference current, and initiating a fluid dispense sequence when the fluid detection circuit detects the presence of the fluid between the flow channel and the ejection chamber.