Hi All,
I noticed that recently an application note appeared on the product page for the Bar30 sensors indicating that sensor must be completely dried once a day. This is also mentioned in this forum post.
Does the Bar100 depth sensor have the same maintenance requirements? We have a requirement for the ROV to be submerged for several days.
Hi @A.Phan,
Both the Bar30 and Bar02 have a gel coating that requires regular drying out. That’s something we’re looking into changing if possible because the sensors would be more useful without it, but in the meantime it’s unfortunately a maintenance requirement of those sensors.
I believe there’s always been a note about that at the bottom of the relevant product pages, and in the sensor datasheets, but we have recently added an extra note about it right at the top of the page since it was coming up as a cause of issues 
Thanks for bringing this up - I recently started compiling a Technical Reference of our products, and that’s not a detail I’d thought to include for the sensors.
On your actual question, the Bar100 uses a different sensor type with no gel coating, so extended submersion is fine. In case it’s relevant, the Celsius temperature sensor also has no issues with extended submersion
Thanks @EliotBR, we will purchase the Bar100 and report back if there are any issues with extended submersion.
I also appreciate the extra note regarding the Celsius temperature sensor.
Just a heads up to others… Unlike the Bar30, the Bar100 is made out of plastic and even a small amount of torque can cause the sensor head to shear off from the thread.
Hi @A.Phan, sorry to see that your sensor head has sheared off. You may wish to contact support@bluerobotics.com to let them know what happened, and discuss whether a refund or replacement may be appropriate.
As a note on this, the Bar100 Technical Details specify a recommended installation torque of “Hand tight or no more than 1.2 N-m”
Hi Eliot,
I think the Bar100 is typically installed with the Hex nut compressing the o-ring from the back to create a seal. Our ROV has been designed with a threaded hole to make assembly easier, this has probably contributed to the shearing.
Is there any option to have the bar100 in the same aluminium enclosure as the Bar30? it seems strange to me that the more expensive sensor comes in a lower quality enclosure.
That’s correct.
Fair enough - I imagine having less wiggle-room during insertion combined with using only the sensor head for tightening would make it more prone to shearing/breakage.
I can ask internally if you’d like, but it would be a single custom item so I imagine it’s unlikely. On the product page it specifies that the Bar100
so I’d assume the stainless steel sensor housing doesn’t enjoy being in an aluminium enclosure.
Right, that is fair enough. For now a custom item may not be necessary we will undertake some testing to see that our mounting method is not prone to leaking. If it is we will reach out regarding a custom item
In case it’s relevant, our 4" 18-hole end cap uses tapped holes for the outer ring, so it’s at least not an unheard of method
That said, as I understand we normally still recommend putting the depth sensor in the central (untapped) hole, but I’d guess that’s mostly for the central alignment (since the ‘base’ depth sensor is a Bar30, which has an aluminium enclosure)