NGM 1 Natural gas module Datasheet The module is equipped with TEST button which allows for triggering of alarm thus providing the means to test the alarming circuitry operation. RS232 communication In addition to visual and audible communication the module allows to monitor the operation using RS232 terminals. Each 21 seconds the module transmits the measurements data. The RS232 communication channel also provides means to calibrate the sensor. Transmission parameters Baud rate 115200bps Description Parity 8N1 The Natural gas module is a battery operated detection device designed for detection of natural Functionality gas (methane) in concentrations below 100% LEL (4.4% CH4 in air). In battery mode the sensor sends data The sensor is equipped with test button as well as through RS232 interface providing one way an audible alarm option realized with embedded transmission only (sensor -> PC). buzzer. Any bi-directional communication can be The heart of the device is an SGX patented MEMS realized using USB connector (sensor should be pellistor sensor which allows for low power detached from battery and connected to PC with operation on standard AA type batteries. installed terminal). In this mode the module is The module is equipped with visual (LEDs) and always in an online state, while measurements are audible (buzzer) alarms to inform of potential gas transmitted each 21 seconds (like in battery leakage as well as transmit data related to actual operation). state of the module and concentration of gas if the module is connected to external receiver working The Natural Gas Module allows for the following with serial RS232 standard. functionality with RS232 communication: The estimated maintenance-free operation on 2xAA 1. Calibration of zero level and gas sensitivity. (2600mAh) batteries is 6 months. 2. Setting up of first alarm threshold. 3. Setting up of calibration concentration. Power consumption 4. Recalling and saving of calibration coefficients. The typical power consumption of the module is <0.6mA on average, with 50mA peak power Please refer to Natural gas module application note consumption at 3V power supply. for detailed information on protocol used. Module operation TECHNICAL PARAMETERS The Natural gas module monitors the concentration Detectable gases methane of methane in air atmosphere. Sensor operates in Maximum 5% v/v. pulse mode measuring actual concentration of gas concentration during 1 second with 20 seconds intervals. Sensor sensitivity >10 mV/% CH4 The sensor is equipped with buzzer and diode Sensor response time <30 s indicators. Zero drift <0.1%v/v /month Depending on actual gas concentration the sensor Sensitivity drift <0..1%v/v /month behaves as indicated in table below: Power supply 5V DC when connected to USB port Gas concentration Module behavior 3V DC when operated < I alarm level Green LED blinking from battery. (normal state) Suggested batteries 2x1.5V AA in series < II alarm level Red LED blinking (min. 2600mAh) > II alarm level Red LED lit all the time Operating current <0,6mA avg + audible sound via (battery operated) buzzer Transmission USB (RS232, CDC Class) Weight 11 g Copyright SGX Europe Sp. z o. o. 2012-2018 Page 1 Natural gas module datasheet Issue 3, August 2018 NGM 1 Natural gas module Datasheet Dimensions w x l x h 30 x 65 x 9 mm Main components MPEL type Signaling diode gas sensor Buzzer TEST button Mini USB connector Battery power supply Mechanical dimensions *All dimensions are in millimeters unless stated otherwise. Special considerations The sensor is equipped with filters allowing it to operate in normal household environment. However sensor should not be subjected to high concentrations of agents containing silicon, sulfide and chlorine compounds (bleach, toilet cleaning agents, silicon greases). If longer exposition to any of the above the overall performance of the sensor might be affected causing limited response to gas. Copyright SGX Europe Sp. z o. o. 2012-2018 Page 2 Natural gas module datasheet Issue 3, August 2018