Our partner TechShop has a welding room with several tanks containing Argon gas to use as the shielding gas during welding. Argon is an odorless, colorless, tasteless gas, and because it is heavier than air it will flow to the lowest spot. Argon gas if released into the room would displace the oxygen causing anyone in the room to pass out, causing harm to them by falling or be the cause of accidental death, due to inert gas asphyxia. In fact for industry, there are reportedly far more deaths every year that result from the use of argon gas than from all other gases combined!
PsIoT engineering team determined that Argon being a noble gas would be difficult to detect and require expensive gas testing equipment. Instead we obtained an oxygen sensor to detect and monitor the oxygen level in the room. The PsIoT system design includes an oxygen sensor, a temperature and humidity sensor, a high output green LED to indicate normal O2 levels, a high output red LED to indicate low O2 levels, and a buzzer that beeps if the O2 sensor is disconnected or sounds continuously if low oxygen levels are detected. In addition to continuous monitoring on a dashboard, a text alert is sent if either of the alarms are enabled. As Argon is heavier than air, we placed the sensor approximately one foot above the floor surface, connected by an audio cable to the PsIoT IoT device mounted on the wall near the ceiling. As the O2 sensor device is a safety device, PsIoT engineers designed a battery backup system that continuously charges a lithium battery allowing the operation of the system to run up to 20 hours without external power.
Our partner TechShop now has a continuous monitor of the oxygen levels in the welding shop area. Users of the welding shop will be alerted by alarm to low O2 condition and the TechShop staff will be alerted to any low oxygen level.
Our partner TechShop has four high performance Laser Cutter's including the Trotec Speedy 300 60W CO2 laser cutter. The laser focus lens requires air cooling or the high power laser will cause the glass lens to overheat and crack. The Trotec laser cutter system includes an air pump that operates to pump air to the laser lens when the laser is on. As the operation of the system is performed by hundreds of users all with different cutting and etching projects and types of projects, and with different skill levels of operating the system, at times the air pump fails or the system programming is changed affecting the operation of the air pump. Without air flow, the laser lens cracks and the Trotec is no longer operational.
PsIoT engineering team determined several ways to detect the operation of the Laser without modifying the Trotec system or integrating in the Trotec system (i.e. modifications to system board to detect laser and pump operation). We evaluated several ways to detect laser operation - a CO2 detection sensor as the laser burns objects but as not all objects are carbon based, it would not detect all operation, evaluated an IR detection to sense the laser reflections but it did not prove sensitive enough (could not consistently detect), a sound sensor to detect the movement of the laser but found the ambient noise level too high, a Hall effect current sensor on the laser power cable, and a light sensor to detect a green LED laser 'on' indicator which is what was selected to detect laser operation as it could be integrated inside the system panel. To determine air pump operation, two sensors were tested, a sound sensor which proved workable but not as reliable as a vibration sensor mounted on the air pump. The PsIoT system continuously monitors the laser operation by detecting the green LED light and the air pump operation with a vibration accelerometer sensor mounted on the pump. An edge algorithm asserts an alarm if the LED is detected and the air pump is not vibrating.
TechShop now has a continuous monitor of the air pump on the Trotec Laser Cutter system to ensure system reliability and operation as well as reduce maintenance costs. The vibration accelerometer can also determine overall pump performance over time and determine by monitoring the vibration data if the air pump operation degrades (increased vibration due to pump wear).