Patent application number | Description | Published |
20110257897 | COMBUSTIBLE GAS DETECTION APPARATUS AND COMBUSTIBLE GAS SENSOR CONTROL METHOD - There is provided a combustible gas detection apparatus with a gas sensor and a control device. The gas sensor includes first and second heating resistors each having a resistance that changes depending on a combustible gas concentration of gas under measurement. The control device includes an energization control section that alternately energizes the first and second heating resistors, a first calculation section that calculates a first calculation value responsive to the combustible gas concentration based on a voltage across the first heating resistor during energization of the first heating resistor, a second calculation section that calculates a second calculation value responsive to the combustible gas concentration based on a voltage across the second heating resistor during energization of the second heating resistor, and an anomaly judgment section that judges the occurrence of an anomaly in the first heating resistor by comparison of the first and second calculation values. | 10-20-2011 |
20120204623 | GAS DETECTOR - A gas detector for use in, for example, measuring the concentration of flammable gas or detecting leakage of flammable gas. The gas detector has a gas detection element in which at least a heat-generating resistor and an insulation layer are laminated on a semiconductor substrate made of silicon while the insulation layer encloses the heat-generating resistor. The gas detector detects flammable gas on the basis of temperature and resistance of the heat-generating resistor which vary according to flammable gas. In the gas detection element, a protection layer in the form of a gas impermeable oxide film is provided on its outermost surface which comes into contact with an environmental atmosphere that contains flammable gas. Thus, alkali resistance is ensured. Since the protection layer is impermeable to gas, entry of impurities (organic silicon) contained in the environmental atmosphere into the protection layer is restrained, whereby output is stabilized and becomes accurate. | 08-16-2012 |
20120247184 | GAS DETECTING APPARATUS AND GAS DETECTING METHOD - A gas detecting apparatus including: a heating resistor exposed to a detected atmosphere, and a control circuit for controlling the heating resistor at two different temperatures, wherein each output voltage from the heating resistor corresponding to the different temperatures is detected when the heating resistor is controlled to the different temperatures, and a state of a gas is obtained based on the detected output voltage. For example, two different offset voltages are set, each potential difference obtained by subtracting each of the offset voltages from corresponding detected output voltages is amplified and the state of the gas is obtained using the amplified potential differences. | 10-04-2012 |
20130298638 | COMBUSTIBLE GAS DETECTION DEVICE - A combustible gas detection device includes an energization control circuit which controls the switching of the energization state of a heat generation resistor every predetermined time period such that the heat generation resistor alternately has resistances corresponding to two predetermined temperatures, a temperature measurement resistor disposed on the same substrate on which the heat generation resistor is disposed, where its resistance changes with the environmental temperature, a gas concentration computation section which calculates the combustible gas concentration by using a voltage generated across the heat generation resistor which is detected when electricity is supplied to the heat generation resistor and the environmental temperature based on a voltage change caused by a change in the resistance of the temperature measurement resistor. The predetermined time period is such that a change in the environmental temperature which occurs when the energization control circuit switches the energization state, falls within a range of 0.5° C. | 11-14-2013 |
20140020448 | COMBUSTIBLE GAS DETECTING DEVICE - A flammable gas concentration detection apparatus ( | 01-23-2014 |
20140053631 | GAS DETECTION APPARATUS AND GAS DETECTION METHOD - A gas detection apparatus includes: a heating resistor; and an energization control unit which alternately switches a temperature of the heating resistor to two different temperatures. The gas detection apparatus calculates a density of combustible gas contained in the atmosphere using a heating resistor voltage in a high temperature period and a heating resistor voltage in a low temperature period; acquires three or more values of the heating resistor voltage in each target period; obtains a first average value of the values of the heating resistor voltage obtained in the target period of the high temperature period; obtains a second average value of the values of the heating resistor voltage obtained in the target period of the low temperature period; and uses the first and second average values for a calculation of density of the combustible gas. | 02-27-2014 |
20160033436 | GAS DETECTION APPARATUS - A gas detection apparatus ( | 02-04-2016 |
20160061756 | GAS DETECTOR AND PROGRAM - A first bridge fixed resistor ( | 03-03-2016 |