Pressure / Temp sensors for Pi system

[JNWRF01]

Hi - just wondering if its an urban myth or not - but can you buy the pressure / temp sensors for the Pi systems from the likes of RS rather than the usual PI retailers. If so - does anyone have a link etc etc. Looking on ebay - what looks like the same pressure sensor to the untrained eye - retails around £20 rather than £60ish from Pi...

[Belatti]

I would like to know this, too.

When I bought liner potentiometers from Pi or AIM, they came in blue boxes with the name of other "sensor" manufacturers...

I think they only thing the sensors have to have to be used is the same impedance (Kilo ohms)

[RF_Racer]

I bought mine from here when I was using an MXL pista on my vauxhall junior.. 2 years of running and never had any issues. becarefull of ebay ones, they are often cheap chinese junk and on a race car due to vibrations would fail very quick.

http://shop1.actinicexpress.co.uk/sh...&search=Search

These guys sell VDO ones, so they are half decent.

[tristancliffe]

VDO sensors are rubbish.

[Casper]

Originally Posted by tristancliffe

VDO sensors are rubbish.

This man speaks the truth.

[RF_Racer]

Indeed they are, but if you read above you will realise he does not want to spend silly money. Better IMO than cheap ebay sensors from china.

Of course, if he has the budget he could go for better ones from PI or MSI.

[flatbroke]

I maybe wrong but the Pi pressure sensors are VDO anyway ??

http://www.tkracingservices.co.uk/Se...sor_0_to_7_Bar

[RF_Racer]

Originally Posted by flatbroke

I maybe wrong but the Pi pressure sensors are VDO anyway ??

http://www.tkracingservices.co.uk/Se...sor_0_to_7_Bar

Looks like it.. Mine was the same a VDO 0-10 bar pressure sensor used for oil pressure. I had mounted it on part of the cockpit roll bars, for 2 years with a lot of vibrations.. didnt fall apart.

If using them I would dampen so not to get a lot of vibrations that a single seater can put it through.

[phoenix]

Originally Posted by tristancliffe

VDO sensors are rubbish.

Hi Tristan

Are they rubbish because they fail, are inaccurate, or both?

I have used them for oil and fuel pressure sensors without any problem that I have noticed.

[tristancliffe]

Accuracy. +- half a bar at best in my experience. Obviously, you can calibrate them correctly, so that that particular sensor is okay, but a replacement sensor would probably give a different value unless re-recalibrated. And for some uses the actual value doesn't matter, it's more the shape of the curve and any dips and bumps that are interesting - e.g. oil pressure. Doesn't matter if you have 3 bar or 2.5 bar really, as long as you don't have dips to zero!

[brown dog]

Originally Posted by tristancliffe

Accuracy. +- half a bar at best in my experience. Obviously, you can calibrate them correctly, so that that particular sensor is okay, but a replacement sensor would probably give a different value unless re-recalibrated. And for some uses the actual value doesn't matter, it's more the shape of the curve and any dips and bumps that are interesting - e.g. oil pressure. Doesn't matter if you have 3 bar or 2.5 bar really, as long as you don't have dips to zero!

yep that sounds right to me. The main problem with the VDO sensor is that they are a "mechanical" type sensor in that they have a wiper on a potentioneter inside that cylindrical case. Vibrations tend to kill them, or make the readings jump around a bit. It is important to isolate them from the engine by means of remote mounting and a length of AN hose and the necessary adaptors. Which of course adds to the weight, cost and packaging arrangement.

[Paceracing]

Pi subcontracts a lot of its sensors to the sensor manufacturers so often you will see similarities however almost all of them are to specially made to Pi specification and not interchangeable. This is done because Pi wants them ruggedised and often includes additional noise filtering to improve signal quality. Some of the sensors also work on different voltages, i.e. 5v instead of 12v and visa versa. This is usually specified by the engineering team and is not done for marketing reasons as is often the misconception. This is particularly true of the professional sensor range where Pi works hand in hand with the major suppliers to produce a top quality sensor.

[greenamex2]

Originally Posted by phoenix

Hi Tristan

Are they rubbish because they fail, are inaccurate, or both?

I have used them for oil and fuel pressure sensors without any problem that I have noticed.

Both.

I have a bin full of failed ones.

At the moment my Omega dash is currently ready 5 PSI oil pressure and and a couple of PSI fuel pressure and the engine hasn't been started for over a day.

Fit some new sensors and it will read completely different incorrect values.

However, and back to the point made earlier, it's good enough for me.

[tzei]

Hi and sorry to resurrekt...

Could someone tell me what are good sensors as if VDO ones are poor.

I would like to get qualty trace for data logging.

AEM has something and Data Spares sells 0-7 & 0-10 bar sensors. Are these for example good?

[greenamex2]

What are you using them on?

[tzei]

The plan is to get pressure (oil and fuel) data first to DTA S60 ecu and then it goes to AIM mxl pista logger.

[greenamex2]

The data spares ones look OK, just normal good quality off the shelf pressure sensors.