Fluid flow sensor with reverse-installation detection
AssigneeTherm-O-Disc, Incorporated
InventorsTimothy Graff, Bernd D. Zimmermann
Life of this patent
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Abstract
A thermo-anemometer-type fluid flow sensor and a method associated with quickly determining whether the sensor has been installed in an improper orientation relative to the direction of fluid flowing through a system. The flow sensor comprises a detection module adapted to change condition in response to the direction of fluid flowing through the system. A control module is connected to the probe and is capable of determining the installation orientation of a probe of the sensor. An I/O module is connected to the control module to provide a means for communicating the output of the control module to another device and/or user.
Claims12
A fluid flow rate sensor comprising:
- a probe comprising a detection module adapted to change condition in response to flow of a fluid through the probe, the detection module comprising:
- means for detecting the flow rate of the fluid;
- and
- means for detecting the installation orientation of the probe relative to the flow of fluid through the probe;
- and
- a control module electrically connected to the probe, the control module monitoring the condition of the detection module and determining whether the installation orientation of the probe relative to the flow of fluid through the probe is reversed.
A fluid flow rate sensor comprising:
- a probe comprising a passageway for accommodating a flow of fluid through the probe and a detection module adapted to change condition in response to the flow of fluid, the detection module housed in a thermally conductive material and disposed within the passageway;
- the detection module comprising:
- a first heating circuit;
- a second heating circuit comprising a resistor heater;
- a fluid flow rate detection circuit;
- and
- a reverse-installation detection circuit having at least one negative temperature coefficient thermistor located in proximity to the resistor heater of the second heating circuit.
A method for determining the orientation of a probe with respect to the flow of a fluid, wherein the probe comprises a detection module comprising first, second, third and fourth temperature sensors arranged in a circuit, a first heater disposed in thermal communication with the first and second temperature sensors, a fifth temperature sensor, and a second heater disposed between the first heater and the fifth temperature sensor, the method comprising:
- measuring a first temperature of the fifth temperature sensor;
- turning ON the second heater;
- measuring a second temperature of the fifth temperature sensor;
- determining a difference between the second temperature and the first temperature;
- comparing the difference between the second temperature and the first temperature with a threshold value;
- if the difference between the second temperature and the first temperature is greater than the threshold value, then generating an alarm;
- and
- turning OFF the second heater.
Dependencies are inferred from the claim text.