The PCE-GA 25 multigas meter is a professional portable detector designed for continuous and simultaneous monitoring of flammable gases, oxygen, carbon monoxide and hydrogen sulphide. It is intended for operator safety and monitoring of potentially hazardous environments where gas leaks, oxygen deficiency or toxic gases may create serious risks for people, systems and equipment. The manual indicates use in areas requiring explosion protection or where toxic gas leaks may occur, such as underground tunnels, mines and industrial environments.

The device detects four main parameters. The Ex channel measures flammable gases from 0 ... 100% LEL, with 1% LEL resolution, low alarm at 20% LEL and high alarm at 50% LEL. The H2S channel measures hydrogen sulphide from 0 ... 100 ppm, with 1 ppm resolution, low alarm at 10 ppm and high alarm at 35 ppm. The CO channel measures carbon monoxide from 0 ... 1000 ppm, with 1 ppm resolution, low alarm at 50 ppm and high alarm at 150 ppm. The O2 channel measures oxygen from 0 ... 30% vol, with 0.1% vol resolution, low alarm at 19.5% vol and high alarm at 23.5% vol.

This configuration makes the PCE-GA 25 suitable for applications where explosion risk, environmental toxicity and sufficient oxygen levels must be checked at the same time. In confined spaces, tanks, tunnels, pits, shafts, technical rooms, poorly ventilated environments or industrial areas, simultaneous measurement of multiple gases is important because danger is not always linked to a single parameter. An environment may present reduced oxygen, flammable gas and CO or H2S concentrations at the same time.

The measuring principle stated in the manual is based on electrochemical and catalytic sensors. Electrochemical sensors are used for toxic gases and oxygen, while the catalytic principle is used for combustible gas detection. General accuracy is ≤±5% F.S. and T90 response time is less than 60 seconds. These data are important for a safety detector because they provide a technical response within a defined time and allow real-time display of the monitored environmental condition.

The LCD display shows real-time status and system status. The product image shows a screen with date, time, battery icon, acoustic alarm icon and simultaneous readings of CH4, O2, CO and H2S channels, with their respective %LEL, %VOL and ppm units. The compact display allows the operator to immediately check the main parameters without changing instrument or using multiple devices. In operational and safety activities, this readability is essential for reducing inspection time and possible interpretation errors.

The detector structure includes status light, sensors, LCD screen, keys, rear clip, alarm light, buzzer and charging position. The housing is made of high-strength technical plastic and anti-slip composite rubber. The manual describes the product as waterproof, dust resistant and explosion-proof, with IP66 protection class. The construction is therefore oriented toward use in harsh industrial environments where impacts, dust, humidity, frequent handling and demanding conditions require a robust and reliable device.

The alarm system is one of the most important elements of the PCE-GA 25. In a low alarm condition, the status indicator lights red, the detector emits a slow acoustic signal, the red alarm light flashes slowly and the device vibrates. In a high alarm condition, the acoustic signal becomes fast, the red light flashes rapidly and vibration warns the operator even in noisy environments or when the display is not directly visible. If the limit is exceeded, the display shows OL and the detector activates a rapid alarm with red light and vibration.

This combination of LED, acoustic and vibration alarm is particularly useful on construction sites, industrial plants, tunnels, mines, production departments and environments where noise, poor visibility or PPE may make a single type of warning less effective. The possibility of temporarily muting the acoustic alarm allows more flexible management, but if the alarm state changes, for example from low to high, the sound is automatically reactivated.

At start-up, the detector performs a self-test of sound, light and vibration. This function is important because it allows the operator to verify that the warning systems are active before using the device in a potentially hazardous area. After the self-test, the instrument shows the low alarm values, high alarm values and range parameters, then after approximately 30 seconds enters detection mode. During normal operation, the status indicator flashes once every 9 seconds to show that the detector is active.

The device integrates menu, calibration and recording functions. From the menu, it is possible to access gas zero, gas calibration, parameter settings, alarm record and device information. Zero calibration allows correction of sensor zero point when the value is within the specified range. Gas calibration, protected by default password 1111, allows calibration points to be set and must be performed according to correct procedures. The manual recommends not arbitrarily modifying factory-set parameters.

The alarm recording function allows records to be read and cleared. In the record reading interface, alarm value, alarm status and alarm time for the corresponding gas channel can be viewed. The symbols L, H, O and P indicate low alarm, high alarm, range exceedance and high concentration protection respectively. This function is useful for analysing previous events, reconstructing abnormal situations and supporting safety or maintenance checks.

The battery is a DC 3.7 V lithium battery with 1800 mAh capacity. Charging time is less than 6 hours and operating time is at least 8 consecutive hours without alarm. This autonomy makes it suitable for work shifts, scheduled inspections, field checks and mobile activities. The manual states that the detector cannot detect gas when it is switched off and charging; it must also not be charged in the test environment to avoid fire or explosion risks caused by sparks during charger connection and disconnection.

The indicated operating range is -10 ... 50 °C with relative humidity below 95% without dew. Storage must be in environments with temperature from 20 to 55 °C and relative humidity not exceeding 85%, in air free from harmful gases or corrosive impurities. The manual also warns not to store or use the detector in the presence of corrosive gases such as Cl2 or in harsh conditions including excessively high or low temperatures, high humidity, electromagnetic fields and strong solar radiation.

Gas sensor life is indicated as 2 years, depending on the operating environment. To ensure test accuracy, the detector must be calibrated regularly and the calibration period must be less than one year. If the device shows inaccurate readings, the manual lists possible causes such as expired sensor or long time without calibration. In these cases, the manufacturer or dealer should be contacted for sensor replacement or calibration should be performed promptly.

For correct use, the detector should be switched on in a safe area, the self-test and start-up phase should be completed, sensors should be checked for dust or obstruction and battery status should be verified. Before entering confined spaces or hazardous areas, the device should be brought to a representative point of the atmosphere to be checked and values should be observed carefully. In case of alarm, the operator must follow company procedures and leave the area if required.

The PCE-GA 25 is therefore a complete solution for multigas monitoring in industrial and potentially hazardous environments. The combination of Ex, O2, CO and H2S detection, acoustic, visual and vibration alarms, robust IP66 housing, rechargeable battery, alarm records, self-test and calibration capability makes it suitable for HSE technicians, maintenance operators, safety teams, confined space workers and professionals who need immediate, simultaneous and reliable environmental control.