Scale Pro

Sentinel Performance Solutions

Why is it better?

The existing offering of water scale inhibitors lacked a basic function – no way of identifying if the unit was functioning. Smallfry incorporated a simple but effective electronic circuit, enabling the user to test if the product was working effectively.

Sentinel Scalepro design ideas
Components of Sentinel Scale Pro

Mechanical Development

Alongside the industrial design of the outer mouldings, Smallfry were asked to deliver a range of feasible mechanical concepts to improve the performance of the descaler.


Fulfilling the brief required a bespoke PCB to be incorporated into the descaler, these were developed in small batches before being finalised for mass manufacture.

Close up of Sentinel product
Inside look at a Sentinel Scalepro design

CAD Development

The final concept was constructed in CAD to realise the intricate moulding features, such as the waterproof battery compartment and internal ribbing to support the PCB.


In order to suite the UK market, Smallfry designed the descaler with regulations in mind. The ScalePro achieved WRAS approval and is recommended in the Compliance Guide to Part L1 of the Building Regulations.

Components of Scale Pro product