Abstract: An example of a gas detection system includes a gas chromatograph oven, a gas detector, a sample gas moving device, and a flow detector. An example of a method for detecting gas includes flowing a sample gas from the oven, determining whether the flow rate equals or is less than a minimum, and determining whether the concentration of a first gas of the sample gas, such as a combustible gas, equals or exceeds a maximum. If either the flow rate or the concentration indicates an error condition or is out of bounds, an alarm response is initiated. The alarm response may include shutting off the flow of the first gas to the oven, and flowing a second gas, such as a safe gas, to the oven.

Abstract: In a single-ended or differential instrument amplifier, an input offset may be adjusted by driving current into the impedance of a feedback network of the amplifier. The amplifier may be provided with programmable gain capability. The impedance does not change with different gain settings, such that the input offset adjustment is equal for all gains. The amplifier may receive the output of a sensor such as, for example, a gas detector such as a thermal conductivity detector. The gas detector may be utilized to measure a gas flowing from a gas source such as, for example, a chromatographic column.

Abstract: An example of a gas detection system includes a gas chromatograph oven, a gas detector, a sample gas moving device, and a flow detector. An example of a method for detecting gas includes flowing a sample gas from the oven, determining whether the flow rate equals or is less than a minimum, and determining whether the concentration of a first gas of the sample gas, such as a combustible gas, equals or exceeds a maximum. If either the flow rate or the concentration indicates an error condition or is out of bounds, an alarm response is initiated. The alarm response may include shutting off the flow of the first gas to the oven, and flowing a second gas, such as a safe gas, to the oven.