EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Psi on June 12, 2022, 11:18:40 pm
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I want to try a DIY fix an LAB mass air flow meter.
It has one broken hot wire sensor. (uses two)
The sensor is a through-hole mounted part that made of 2 thin gold plated metal posts and a hairline wire (with blob in center) attached across the tips of the posts.
Anyone know where I can order one of those from. Doesn't have to be exactly the same part, there is no part number on it anyway.
I'm happy to hack any part in there and just see what happens. (I have the service manual with access to cal the hot bar sensor)
I'm just having troubled actually finding the hot wire part to purchase.
It's probably on aliexpress somewhere if i could find the right search terms.
Anyone know?
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Good luck, probably better off buying the cheapest aliexpress MAF for a car
It's usually platinum, or platinum film over something (glass, tungsten, etc).
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Drop this into Google for plenty of local hits:
resistive platinum wire nz buy
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Good luck, probably better off buying the cheapest aliexpress MAF for a car
It's usually platinum, or platinum film over something (glass, tungsten, etc).
Yeah, that was my back idea. lots of $20 MAF sensors on aliexpress.
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Can you post a picture to see?
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Can you post a picture to see?
I wish i had taken a photo when it was apart. Ill try to get another one
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How to fix the wire this is the important question。Is the wire welded to the post or is it pressed and clamped to the post?
This is why I need to see real photos
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Does anyone know if these MAF wires use any kind of standard alloy or are there different alloys?
If standard then perhaps the OP can get a wire from the MAF sensor from a scrapped auto engine. But I suspect that it would have to be the same alloy, the same o.d. and the same length as his original in order to work correctly in his application.
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Here's some photos
There's 2 sensors, both different height, one is fine, the other is broken.
Its a 4000 series TSI flow sensor.
(https://www.eevblog.com/forum/testgear/where-to-buy-through-hole-hot-wire-mass-airflow-sensor-wire-for-diy-fix/?action=dlattach;attach=1529002;image)
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This is a TSI gas flow meter.A friend I know has a similar tool that is used to test the airflow calibration of ventilators and anesthesia machines.
Do you know the resistance value of this wire damage?
I remember that the wire was not made of copper. If you want to solder a length of wire of the right length, first electrolessly coat both ends with a copper material suitable for soldering.(https://youtu.be/tUKesnyqqO4)
There is also a need for flow calibration after replacing a new sensor, because each sensor is different.
(The calibration code can be stored in EEPROM or inside the microcontroller. I didn't find the memory chip or control microcontroller in the picture. You may not have sent all pictures.)
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Yeah, it seems like a lost cause and not really worth the time fixing.
I was just curious if I could buy a replacement hotwire and solder it in, but doesn't look like it.
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Calibration is an important issue, only ensuring accuracy is the most important.
Is there a memory chip on the motherboard?
2 kinds of hot wire sensors, one is to measure the flow and the other is to measure the temperature?