Description
Buy online for small quantities. For large quantities, projects and repeat business send a quotation request to: sales@birkettcontrols.com.au
The FineTek SD-20 is a compact optical level switch for point level detection of liquids, using an infrared prism sensor with no moving parts. The SD-20 detects the presence or absence of liquid at the sensor tip by measuring the total internal reflection of light within a prism. When the tip sits in air, the light reflects internally back to the receiver; when liquid covers the tip, the light refracts out through the prism face and the receiver registers the change. With solid-state electronics and no float, paddle or other mechanism, the switch is compact, robust and easy to remove, clean and reinstall. Built-in LED indication shows the switching status at a glance.
No Moving Parts
Detection relies entirely on the optical prism and solid-state circuitry, so there is nothing inside the switch to jam, wear or foul. This makes the SD-20 well suited to clean liquids and to applications where mechanical float switches are prone to sticking or contamination.
Housing and Tip Materials
Two material families are offered to suit the medium and pressure rating. Plastic versions use a PC or PES housing and tip, suitable for water, oil, liquid solutions, alcohol, organic solvents and mild acids and alkalis. Stainless steel versions use a SUS304 or SUS316 housing with a PES tip for higher pressure and more demanding process conditions. PES (polyethersulfone) is comparable to PSU (polysulfone) but offers better heat resistance, strength and stiffness.
Flexible Output
The switch provides NPN or PNP open-collector output, available as either normally open (NO) or normally closed (NC), to energise a relay or PLC input directly. Reverse polarity protection and short circuit protection are built in.
Process Connection Options
A range of thread and connection sizes is available. Plastic versions offer M12x1.0 or 3/8" connections with PF or NPT threads. Stainless steel versions offer 3/8" or 1/2" connections with PT, PF or NPT threads. Cable or M12 connector termination can be specified depending on the variant.
The SD-20 is available in a range of housing materials, connection sizes and output configurations to suit the installation.
Currently stocked in the configurations shown in the above list. Delivery time for non-stocked configurations is typically 4-6 weeks.
To order a configuration not included in the above list or for application advice, send your request to: sales@birkettcontrols.com.au or contact us for more information on 02 9560 8593
Typical Application Areas:
Pharmaceutical systems
Food and beverage systems
Hydraulic reservoirs
Industrial compressors
Air conditioning systems
Machine tools
Processing and packaging equipment
Heavy-duty automotive
Liquid holding tanks and sumps
