System and method for automatically adjusting gas sensor settings and parameters
An automatic sensor excitation voltage adjustment feature, a multi-range concentration feature, a single calibration feature and a barrier circuit feature. The automatic sensor excitation voltage adjustment feature includes a transmitter having a transmitter microprocessor that provides an initial voltage to a sensor having a sensor microprocessor. As the voltage changes a correction signal is relayed from the sensor microprocessor to the transmitter microprocessor. The correction signal is used to adjust the voltage applied to the sensor. The multi-range concentration sensor feature includes an amplifier associated with the sensor/microprocessor to create gain settings used to optimize sensor resolution by changing a gain value for the sensor. This enables use of a single sensor for a variety of different concentration ranges. The single calibration feature enables a sensor to be calibrated at a single gas concentration value, and thereafter be used for a variety of different concentration range applications. The barrier circuit feature provides for intrinsically safe power and communication signals to the sensor.
1. A system for detecting the presence of a gas, comprising:
a sensor portion, having a sensor processor, for sensing a target gas and providing signals indicative of the gas;
a transmitter portion for transmitting information received from the sensor portion to a network, the transmitter portion including a transmitter processor;
a variable voltage power supply associated with the transmitter portion and configured to supply voltage from the transmitter portion to the sensor portion for operation of a sensor of the sensor portion, the variable voltage power supply including a plurality of potentiometers to provide coarse and fine adjustment of the voltage supplied to the sensor portion; and
a barrier circuit for limiting at least one of current, voltage and power to the sensor portion;
the sensor processor being configured to:
determine a voltage received from the transmitter portion; and
communicate the determined voltage to the transmitter portion; and
the transmitter processor being configured to manipulate at least one of the plurality of potentiometers to adjust the voltage supplied to the sensor portion for operation of the sensor based on the determined voltage.
2. The system of claim 1 , wherein the sensor processor is further configured to:
determine a loss of sensor sensitivity has occurred; and
adjust at least one gain parameter based on the determined loss of sensor sensitivity.
3. The system of claim 1 , wherein the sensor portions include an infrared gas sensor, a catalytic bead sensor, an electro-chemical sensor, a photo-ionization sensor, a metal-oxide sensor and combinations thereof.
4. The system of claim 1 , wherein the barrier circuit includes a zener diode.
5. The system of claim 1 , further comprising a second barrier circuit for limiting at least one of current, power or voltage with the sensor portion.
6. A method for adjusting sensor excitation voltage, comprising:
providing, from a transmitter portion including a transmitter processor, an operating voltage to a sensor portion for operation of a sensor of the sensor portion;
determining, at a sensor processor of the sensor portion, a voltage received from the transmitter portion;
communicating, by the sensor processor, the determined voltage to the transmitter portion; and
manipulating, by the transmitter processor, at least one of a plurality of potentiometers of a variable voltage power supply associated with the transmitter portion to adjust the voltage supplied to the sensor portion for operation of the sensor based on the determined voltage.
7. The method of claim 6 , further comprising:
determining a loss of sensor sensitivity has occurred; and
adjusting at least one gain parameter based on the determined loss of sensor sensitivity.