Thanks a lot Dansole.
Please share your code. I want to take idea.
In fruit business necessary to measure ethylene up to 1000 ppm. All mentioned sensors are 100ppm.
Where is possible to buy ETHYLENE sensor with 1000 ppm range?
You can definitely get sensors up to that range, higher concentration sensors are actually more common up to the LEL of a given gas:
When you measure up to such a high range you won't have good resolution at lower concentrations.
In my experience it is the lower levels that are more important for maintaining fresh produce.
Interested to know more about your application though.
dan
Hi dansole,
Can ethylene be detected using generic VOC PID sensors?
Do they have less accuracy as compared to dedicated ethylene sensors mentioned before in this thread?
Thanks
EDIT:
Thanks dansole, I will have to opt for dedicated ethylene sensors for better detection and less distraction from other gases.
Found this sensor specifically designed for ethylene detection in agricultural/fruits scenario and has auto-calibration too
Thinking to go for this sensor instead of the one mentioned earlier in this thread (Winsen ZE11 C2H4 High-performance Gas Detect Electrochemical Module for Arduino | eBay)
Hi austin_fr,
Do you have a particular sensor in mind? Share the link.
Sensors that detect VOC's in general will pick up the ethylene but will also pick up a lot of other things like alcohol, CO2 etc and sometimes respond more to those chemicals than the ethylene which completely overwhelms the response due to ethylene.
If you were using it to measure a pure gas mixture like ethylene in N2 it would work but otherwise it will have limited application.
@dansole @developerunify thanks very much for all the information you've put on here. I'm unsure as to whether either of you are still about on these forums, but if you are, might I ask for your help also?
A friend of mine is currently doing an experiment using a Photoionization sensor, called a minipid 2 and the related sensor's PCB, as detailed here (basic overview):
https://www.ionscience.com/wp-content/uploads/2018/12/SDK-V1.0-US-for-web.pdf
and here (detailed spec):
https://www.ionscience.com/wp-content/uploads/2018/12/SDK-Manual-V1.2.pdf
I have seen mention of PID sensors within this thread, which is why I'm posting my question here, as you two seem to have a decent working knowledge of how such sensors can be connected to an Arduino. I haven't worked with these types of sensors before, but I have used other sensors in the past, and have suggested to my friend that an arduino might help her in her experiments.
From what I can see, the sensor's pcb board has VCC, Ground, Signal+ and Signal- connections. The current way my friend is using the PID sensor is powering it with batteries via the sensor board, and then the two signal cables are hooked up to an audio jack adapter and plugged into a data logger.
The data logger isn't ideal for the experiment she is doing though, ideally using an arduino board would be much better due to having more control of how the data is processed and sent to other devices.
--- My main question here is (after that dump of background information), how would I go about connecting the arduino to the sensor board shown in the above PDFs? ---
I'm thinking that the arduino could be powered by batteries/other means, and feed the power/ground into the sensor board, with the two signal wires plugged into the RX/TX. Would this work? I don't want to suggest something to her that may damage the sensor or the sensor board since, as you both know, these sensors aren't exactly cheap!
Any help you could provide would be super appreciated, I'd be very grateful! I'm actually a mobile applications developer, when it comes to arduino related things I'm more into creating custom bluetooth controllers for applications and games etc., so when it comes to precision instruments I'm a bit lost. If you can help out and ever need any mobile application help I'd be more than happy to help you out in return 
Thanks guys!
Configuring it as a MODBUS slave seems useful - various values you can read then.
I think its using RS485 for MODBUS, so you'll need an RS485 shield or module.
HinaAfreen:
Thanks a lot dansole. I have read and see all descriptions and images you shared.
- Is C2H4 sensor is separate from board and you had calibrated the sensor by yourself and attach with board?
- You have to avoid applying pressure to the sensor using a cap like the one in the photo with gas applied slowly using a tube into one hole with the other hole open.
i can not understand this?- Eth conc. = [(reading voltage - zero voltage) / 100ppm voltage - zero voltage] * 100
thanks for this specially.- Did you use external power supply adapter as shown in setup?
good day. my name is janrey from the philippines. i have a study abut fruit ripening and i purchased a sensor with ME4-C2H4 attached to ZE11 module for arduino. I will use this to read ethylene concentration in ppm.
i have zero knowledge with arduino and can you help me enlighten some of the outputs i need to use. there are 3 outputs
UART OUTPUT ; DAC (0.4～2V standard voltage output); Sensor amplified voltage signal
can you help me with the code? thank you so much.
Hi Janrey,
Happy to help however I can.
I haven't used the ZE11 board but it looks like it outputs either serial (UART) or analog signal based on the gas concentration.
The UART would take some decoding, you would need to look at the documentation to explain how it outputs the signal. If you are not that familiar with programming it might be difficult.
The analog should be easy enough to use by connecting to an analog pin on the arduino.
In the attached you can see that pins 2,3 and 4 can be used as a minimum for hooking up to an arduino and reading the concentration.
Pin 3 is GND
Pin 4 is 5V voltage input
Pin 2 goes to any analog input (eg. A0) that you want to read
If you hook it up in this way and upload the first arduino example to it you should be able to read the voltage in the Serial output window.
then you need to convert the signal from voltage to ppm.
The datasheet say 0.4v = 0ppm and 2V=100ppm
You will need to test this with a standard gas and a standard will be required to recalibrate as the voltage output will drift over time.
Hope this helps.
Feel free to get in touch if you need more help.
dan