Disassembled an ethylene oxide detector, using the STC microcontroller

littleshrimp

Disassembled an ethylene oxide detector, using the STC microcontroller [Copy link]

 

 

Recently, because I may be exposed to ethylene oxide gas at work, for safety reasons I bought a second-hand ethylene oxide detector to study its principles and to test it to see if there is any large-scale leakage.

This detector is produced by Henan Zhongan. It costs nearly 1,000 yuan for a new one, which is neither expensive nor cheap. The appearance and workmanship are OK. However, when I set the time, I found that the month can be greater than 12, and the date can be set to 100 at most. I feel that this logic is wrong and it is not something that a normal programmer can write, so I suspect that this thing is fake.

After opening it, I found that the workmanship inside was really amazing. I have disassembled many electrical appliances, but this is the first time I have seen such pure hand-welding.

There will be residual solder oil on the chip and the board. The STC of the microcontroller is not very noticeable, which is normal. However, the yellow flying wire on it is a bit unreasonable.

This meter has a CH341 USB serial port chip, which should be able to read the meter's data or configure something via a PC.

Although it is hand soldering, I think this welder cannot reach this level without a few years of experience. Look at the capacitor below, it is directly soldered to the pin of the chip without a solder pad. It is difficult for ordinary people to do this.

The crystal oscillator housing is also grounded, which is quite thoughtful. It seems to be prepared for inspection, and it may also be considered for impact protection.

The quality of the sensor connection column is also good, and the amplifier is ADI's AD8607A, which is luxurious.

This flying line is also very luxurious. It could have been solved by a few millimeters, but they actually used several centimeters at the cost.

This type of soldering seems to be no less advanced than reflow soldering.

The sensor used is SolidsenSe's 4ETO-100, a German-made 100ppm range ethylene oxide sensor.

Gold-plated pins, the workmanship doesn't look like a fake sensor.

After disassembling it, I am a little confused. I can't tell whether it is real or fake. I posted a video before, and some people said that this should be real, but based on my experience, it doesn't look like it. If anyone knows about it, please help analyze it.

吾妻思萌

The item is real, the craftsmanship is real, the code is real, but when they are assembled together, it becomes fake~

sint27

Hand-soldering a thousand dollar item with flying leads...

秦天qintian0303

Sometimes this kind of thing is just selling a concept, so if it's unique, you don't have to be so rigorous.

xutong

Looks like a graduation project with a shell

whuer

sint27 posted on 2023-2-13 08:14 A thousand-dollar item is hand-welded with flying wires. . .

Russia has over one million devices with wires flying everywhere

tagetage

This is a prototype. It looks real, but the developer must have just graduated.

yubinwu

No batch, that's it.

soso

This time, there was an assistant beside me, and it felt good to chat with each other, haha

littleshrimp

Azuma Simeng posted on 2023-2-13 06:41 The thing is real, the craftsmanship is real, the code is real, but when assembled together it becomes fake~

Is that true?

littleshrimp

sint27 posted on 2023-2-13 08:14 A thousand-dollar item is hand-welded with flying wires. . .

Isn't it amazing?

littleshrimp

Qintianqintian0303 posted on 2023-2-13 08:52 This kind of thing is sometimes about selling concepts, and if it is unique, it doesn’t need to be so rigorous

This meter also has models for detecting other gases. It should be fine to just change the sensor and the code. Ethylene oxide is not used much, but there are still many competing products for combustible gases.

littleshrimp

xutong posted on 2023-2-13 10:18 It looks like a graduation project with a shell

It is similar to the graduation project

littleshrimp

whuer posted on 2023-2-13 11:09 Russia's more than one million devices also have flying wires everywhere

Mine may be an early prototype, and it seems to have a certain collection value.

littleshrimp

tagetage posted on 2023-2-13 12:44 This is the prototype, it looks real, but the developer should have just graduated.

Maybe PCBs were more expensive at that time, and re-sampling was too costly.

littleshrimp

yubinwu posted on 2023-2-13 13:36 No batch, just like this

I see that the products sold by JD now have anti-counterfeiting labels on the back, but mine don’t, which means there are probably still fakes out there.

littleshrimp

soso posted on 2023-2-13 17:23 This time there is an assistant beside me, and it feels good to chat with each other, haha

It's much more interesting than recording videos by yourself at home.

xutong

littleshrimp posted on 2023-2-13 20:48 It is similar to the graduation project

Excellent graduation project

lansebuluo

The workmanship looks good from the outside, but the manual welding seems to be done by a novice. Maybe it was designed by one person, and the design and program are both very good, but the welding is not so good. No one is perfect, so it is understandable.

damiaa

Prototype. First prototype. Second prototype. Some of them are not flying yet. Small batches are not ready yet. The product is very real. Handmade.

You can also update the program directly via usb-uartttl.