A computer system for detecting a gas leak, the computer system comprising: communications circuitry configured to receive, from a user device, an electronic indication of a monitoring mode for an ultrasonic gas leak detection device (100, 200); monitoring mode determination circuitry configured to determine whether the monitoring mode corresponds to a standard mode or a focus mode; ultrasonic gas leak monitoring circuitry configured to in response to a first determination that the monitoring mode corresponds to the standard mode, monitor a first range of ultrasonic frequencies to generate a first set of monitored data (302, 312, 402), wherein the first range of ultrasonic frequencies is from about 20 kHz to about 30 kHz, and in response to a second determination that the monitoring mode corresponds to the focus mode, monitor a second range of ultrasonic frequencies to generate a second set of monitored data (304, 314, 404), wherein the second range of ultrasonic frequencies is from about 50 kHz to about 70 kHz; and ultrasonic gas leak detection circuitry configured to in response to the first determination that the monitoring mode corresponds to the standard mode, generate a first ultrasonic gas leak detection signal based on the first set of monitored data (302, 312, 402), and in response to the second determination that the monitoring mode corresponds to the focus mode, generate a second ultrasonic gas leak detection signal based on the second set of monitored data (304, 314, 404). communications circuitry configured to receive, from a user device, an electronic indication of a monitoring mode for an ultrasonic gas leak detection device (100, 200); monitoring mode determination circuitry configured to determine whether the monitoring mode corresponds to a standard mode or a focus mode; ultrasonic gas leak monitoring circuitry configured to in response to a first determination that the monitoring mode corresponds to the standard mode, monitor a first range of ultrasonic frequencies to generate a first set of monitored data (302, 312, 402), wherein the first range of ultrasonic frequencies is from about 20 kHz to about 30 kHz, and in response to a second determination that the monitoring mode corresponds to the focus mode, monitor a second range of ultrasonic frequencies to generate a second set of monitored data (304, 314, 404), wherein the second range of ultrasonic frequencies is from about 50 kHz to about 70 kHz; and in response to a first determination that the monitoring mode corresponds to the standard mode, monitor a first range of ultrasonic frequencies to generate a first set of monitored data (302, 312, 402), wherein the first range of ultrasonic frequencies is from about 20 kHz to about 30 kHz, and in response to a second determination that the monitoring mode corresponds to the focus mode, monitor a second range of ultrasonic frequencies to generate a second set of monitored data (304, 314, 404), wherein the second range of ultrasonic frequencies is from about 50 kHz to about 70 kHz; and ultrasonic gas leak detection circuitry configured to in response to the first determination that the monitoring mode corresponds to the standard mode, generate a first ultrasonic gas leak detection signal based on the first set of monitored data (302, 312, 402), and in response to the second determination that the monitoring mode corresponds to the focus mode, generate a second ultrasonic gas leak detection signal based on the second set of monitored data (304, 314, 404). in response to the first determination that the monitoring mode corresponds to the standard mode, generate a first ultrasonic gas leak detection signal based on the first set of monitored data (302, 312, 402), and in response to the second determination that the monitoring mode corresponds to the focus mode, generate a second ultrasonic gas leak detection signal based on the second set of monitored data (304, 314, 404).