This power sensor is an accessory for Arduino and similar microcontrollers. The kit includes the power sensor and a cable to connect it to an Arduino. It does not include an Arduino or a micro controller.
Our Power Sensor is an affordable piece of kit to check your infrared 10.64μm CO2 laser tube. This allows laser cutter owners and hobbyists to measure the power in Watts of their CO2 laser cutter keeping track of it's power over time.
At the moment we supply it as the Sensor only, you will have to hook it up to an Arduino The calibration data is stored on the probe and written on the sleeve of it's cable.
High power lasers are dangerous and emit laser radiation. A stray or even unfocused laserbeam at 10.6uM can set materials on fire and causes permanent damage to human tissue. All interlocks should be engaged and all panels on your cutter shut. The high voltage generated at the anode of the tube is discharged at the cathode where the beam leaves the tube. Mount the sensor on the stainless tube and do not hold it with your hand. 10.6 μm laser radiation, even stray, causes permanent damage to your eye. Wear laser safety goggles!
- PowerSensor calibrated and labeled with it's ID and calibration data.
- Matching JST SM 2,54mm plug with wires
- 4,7k Ohm Resistor
- usable for 20-150W infrared CO2 laser tubes.
- accuracy: ±5W
To measure the power of a laser tube you fire the laser at a target of known thermal capacity for a know amount of time and measure the temperature increase that causes. The power probe consits of a block of black anodized aluminium with a digital temperature sensor in it. The black anodizing absorbs the infrared laser beam and transfers the heat to the aluminum block. A 1-wire temperature sensor inside the block measures the rise in temperature while the laser is firing.
In simple terms shoot your laser at the block of anodized aluminum, aim to widest side, in the middle. It is suggested that you use a "helping hand" or "third hand" as used for soldering assembly to hold the block in the beam, using a crocodile clip at the wire close to the anodised block. Try to ensure that anodized block is not in contact with any other material or conductors. Ensure that the enodised block is not in contact with the cathode wire (or close enough to make a contact) and is not touching the mirrors or lens. It is best to test the power of your laser beam unfocused. That is do not test your beam focused, beyond the lens, as the intense beam may harm the anodization.
The JST SM receptical attached to the power seonsor only has 3 pins in a 4 wire housing for futre expansion.
| Pin | color on sensor | color on plug | Arduino Pin |
|---|---|---|---|
| 1 | yellow | black | A0 |
| 2 | green (unused) | ||
| 3 | red | red | 5V/3,3V |
| 4 | black | blue | GND |
Connect the probe as follows:
blue wire to any GND pin red wire to 5/3.3V black to A0
Now add a 4,7k Ohm pullup resistor between the red and black wire.
The green wire unsued and remains unconnected.
To write the software to your Arduino you will need the Arduino IDE:
https://www.arduino.cc/en/Main/Software
And the "DallasTemperature" library which can be installed via the library manager: https://www.arduino.cc/en/Guide/Libraries
Download this repository and flash the sketch to your Arduino https://github.com/GitNMirrors/PowerSensor/archive/master.zip
You will have to set your laser controller up to fire at full power for 20s.
During these 20s the power probe will get hot! Especially with lasers above 50W it's temperature will exceed 60°C!
Some controllers can only be set to fire for 10s (Ruida) it is okay to fire those for a second 9999ms shortly after the first.
Connect your Arduino with the PowerSensor to your computer and in the Arduino IDE open the Serial Monitor at 115200 Baud.
Mount the sensor block on the stainless tube sticking out of the black block or suspend the sensor on it's cable just in front of the laser tube. Follow the intructions in the serial terminal and fire the laser for 20s.
Keep in mind, that the block stays hot afte the mesurement for a while.
"This probe has been tested and calibrated and provides an indicative indication of tube wattage, it is not intended to be a definitive measurement and is not certified."