Regardless of which type of alarm you prefer, you should make certain that you will be alerted from any area of your home. An alarm which is not noticeable will not help you. Most gas detectors are either battery operated, or have a battery back-up system for 110 volt electrical power supply. Remember to check the batteries and the alarm regularly. Some gas detectors will also warn you if there is a power loss or other malfunction.
Gas detectors use sensors to find out if there are dangerous levels of natural gas nearby.
Like batteries, sensors can wear out. When purchasing a gas detector, ask about the average life of the sensor, as well as if there is a warning when the sensor needs replacing. You may also want to know whether the sensor can be replaced if it wears out, and the price of a new sensor. Some types of gas detectors must be calibrated in order to keep functioning properly. Ask if the gas detector model that you are interested in will require this service.