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Bar100 expandable to 2000m?

I’m very interesting by your Bar100 product. I’m a French engineer and i have to develop an Autonomous Underwater Instrument [AUI] dedicated to take submarine video on ecosystem in Austral Sea by 2000m depth!!
So i would like to add a depth sensor in order to record the depth on embedded memory.
I contacted KELLER ,LD pressure sensor series are qualified for 100bars but the accuracy is given for 0.3%FS so 0.3% x100bars = 0.3bars!! so in depth: 30cm!!
On your website your Bar100 is given for an accuracy of 3mm? Could you explain this difference? It’s a "customized Keller " sensor?
My goal is to buy a 9LD Keller calibrated for 250bars with the same incredible accuracy!!
Waiting for your reply,

Hi Marc,

Thanks for the questions!

The accuracy and resolution are different things. The resolution of the sensor is 3cm, meaning that the smallest change that the sensor can perceive is 3cm. The accuracy is wider than that and that is what the 0.3%FS refers to. 0.3% x 100 bar = 0.3 bar = 3 meters of accuracy.

What this means is that if you’re at some depth, let’s say 100 meters, then the sensor will be able to detect movements up and down in the water column as small as 3 cm, but the accuracy could be off by 3 meters. So, maybe the sensor reads 100 meters, but the ROV is actually at 97 meters, but still able to detect small changes up and down.

The Keller 7LD sensors are available in other ranges, so it would be possible to make one for 2000 meter depth. If you want to go deeper than that then you have to use a different model. I’m not familiar with all of the options.

I hope this helps! Let me know if this makes sense.


Hi Rusty,

Thanks for these informations, i made confusion between resolution and accuracy!!
I received a quote around 150€ for the 7 LD series Keller sensors.
Thanks for your prompt reply
The BlueRobtics forum is really a very precious technical help for us just beginners in ROV wonderful world!!!

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Marc - Glad that’s helpful. Good luck!