Pressure sensor membranes - Page 1
Forum section: electronics / beginners

author: Ram80
author_rank: Contributor
timestamp: September 14, 2024, 07:48:33 am
content: Does anybody have any experience using membrane pressure sensors. I want to build a device that measures water pressure, drops of rain, and want to use a membrane sensor to do this.There are various different technologies such as FSR, Capacitive , Pressure Sensors, piezoelectric, Piezoresistive, optical, strain gauge, MEMS, Resonant, Inductive.And there's the issue of making it waterproof.Would something like this be able to do the job?￡1.60 | Load Cell Resistive Membrane Pressure Sensor Module Flexible Force Sensitive Analog FSR402 4mm 5mm 7mm 110mmhttps://a.aliexpress.com/_EHIBSc9

author: Poroit
author_rank: Frequent Contributor
timestamp: September 14, 2024, 08:53:01 am
content: Are you wanting to measure rainfall?

author: Ram80
author_rank: Contributor
timestamp: September 14, 2024, 09:05:52 am
content: Quote from: Poroit on September 14, 2024, 08:53:01 amWell rainfall was just an example, water pressure in general such as flowing water in a cavity. So I need the right sensor, for it to be waterproof or able to be covered by waterproof material and it took be sensitive and accurate enough for water pressure to activate the sensor.

author: voltsandjolts
author_rank: Unknown
timestamp: September 14, 2024, 10:32:34 am
content: I work with water pressures up to 15,000psi.What pressure range do you wish to measureexactly?

author: Ram80
author_rank: Contributor
timestamp: September 14, 2024, 12:39:00 pm
content: Quote from: voltsandjolts on September 14, 2024, 10:32:34 amVery small compared to 15k psi probably up to 5psi.

author: voltsandjolts
author_rank: Unknown
timestamp: September 14, 2024, 03:42:52 pm
content: OK, I assume that's 5 psig (gauge pressure, so 0-5 psi above local atmospheric pressure, which is roughly 14.7 psia at sea level).What sort of device do you want to build?...Do you want a standalone unit with a display?Are you going to be programming a microcontroller, or should this be a 'hardware only' solution (e.g. op-amps only)?

author: Ram80
author_rank: Contributor
timestamp: September 14, 2024, 03:53:43 pm
content: Quote from: voltsandjolts on September 14, 2024, 03:42:52 pmA device that will measure the pressure of a flow of water, probably into a cavity .I don't really need a display, I thought a nand ram chip and USB so I can transfer data.Yes it will have an MCU like the stm32,I'm new to these sensor and don't know what their capabilities are, for example if you drip water onto these sensors would that register a reading or if your flowed water onto them would they be sensitive enough to measure a range of different water pressures.

author: Poroit
author_rank: Frequent Contributor
timestamp: September 15, 2024, 08:11:46 am
content: So 5psi gauge.How are you planning to install the pressure transducer?Do you want a threaded male process connection?

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 15, 2024, 11:07:27 am
content: I am not sure if the OP wanted a pressure sensor. I think the OP wanted to measure the force of the water drop striking the sensor or a flow meter. To have 5PSI of pressure the water has to be collected in a vessel 138 inches deep.

author: voltsandjolts
author_rank: Unknown
timestamp: September 15, 2024, 12:38:37 pm
content: The OP is very vague on what is actually required, so it's hard to help.

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 15, 2024, 01:16:15 pm
content: There is little pressure for what the op is trying to measure. I think it's best to use capacitive sensor.

author: voltsandjolts
author_rank: Unknown
timestamp: September 15, 2024, 03:07:10 pm
content: OP wants to measure "pressure of flow"...so it's not clear to me if they actually need a pressure sensor or a flow sensor

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 15, 2024, 05:59:38 pm
content: Yes and the sensor the OP wanted to buy is a load cell which measures force acting on it not a pressure sensor.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 15, 2024, 06:12:05 pm
content: Those membrane force sensors probably have applications, but my experience trying to use them for calibrated responses leads me to recommend against it. The are cheap, small and easy to interface but the good ends there. Drift or aging is huge and the response is very sensitive to the shape and location of the force application.

author: Ram80
author_rank: Contributor
timestamp: September 15, 2024, 08:01:17 pm
content: Quote from: CatalinaWOW on September 15, 2024, 06:12:05 pmThis is what I was looking for, that they are not really suitable due to lack of accuracy. I've since discovered dedicated pressure sensor transducers. They will probably be the best bet. Such a learning curve.

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 16, 2024, 09:25:17 am
content: Quote from: Ram80 on September 15, 2024, 08:01:17 pmI still don't know what you try to do. Can you explain further?