Capacitive linear encoder
KappaSense FREEe capacitive linear encoder
Capacitive absolute linear encoder with a passive 3 g read head and no moving cables; several heads can share one scale.
Need this part, a replacement or a complete package? Our experienced UK engineering team helps you select, source and obtain the right products, with pricing, delivery coordination and after-sales support.
Pricing and availability
Get pricing, sourcing and replacement support
Need KappaSense parts, a replacement or a suitable alternative? Send us a part number, or tell us what the machine needs to do. Our UK engineers will come back with the right product, pricing, lead time and delivery, whether that is the original part, a checked alternative or a complete axis.
- Original parts or a checked alternative
- Pricing, lead time and delivery in one reply
- Components, complete axes and ongoing support
No obligation. Add what you know and an engineer will help with the rest. Prefer to configure it? Build a specification.
Spec builder
Configure KappaSense FREEe
Select every part you need and answer the questions an applications engineer would ask. Our engineers use your specification to come back with the right products, pricing and lead times. You see your summary before we ask for any details.
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- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
What are you specifying?
Select everything you need. A motor, drive and gearbox can be specified together as one axis.
Key specifications
| Linear speed (max) | 6 m/s |
|---|---|
| Accuracy | +/-5 um |
| Interface | BiSS-C, SSI (contact for availability) |
| Resolution | 0.5 |
| Repeatability | +/-1 um |
| Stroke | 280 / 800 |
| Temp | -40 to +85 C |
Series ranges as published; individual models vary. The full datasheet, drawings and CAD models are available on request.
KappaSense FREEe replacement and alternative options
Use these supply-network options as a starting point for an engineering check. We can also help source the original KappaSense part. Published series figures do not establish an exact-model or drop-in replacement: confirm ratings, fit, interfaces and approvals for your application.
Absolute linear magnetic read head for LMSA scales, 1 µm resolution, up to 10 m/s, IP67.
| Published maximum | FREEe | ALS21 |
|---|---|---|
| Speed | 6 m/s | 10 m/s meets or exceeds |
Rugged incremental head with RS422 or HTL output and 10-30 VDC supply option. Works on linear and rotary scales.
| Published maximum | FREEe | IKS23 |
|---|---|---|
| Speed | 6 m/s | 16 m/s meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
Options
- absolute or incremental
- multiple read heads per scale
Typical applications
What a capacitive linear encoder is
A capacitive linear encoder measures position along a straight axis by sensing capacitance between electrodes on a readhead and a patterned scale. As the readhead moves, the capacitance pattern changes, and electronics calculate absolute or incremental position. Scales can be printed circuit strips or flexible substrates, and some designs use passive readheads with no cable on the moving part. Capacitive linear encoders are unaffected by magnetic fields and can tolerate wide mounting tolerances.
When engineers choose a capacitive linear encoder
Choose a capacitive linear encoder for robust, cost-effective absolute position on axes near magnets or where moving cables are a problem, such as linear motors, actuators, medical and laboratory devices. The trade-offs are moisture sensitivity and accuracy: water or conductive films between head and scale affect readings, and accuracy is typically below optical scales. For precision metrology choose optical; for wet or very dirty conditions consider inductive or magnetic.
How to specify the KappaSense FREEe
Send these with your enquiry and an engineer can confirm the right FREEe variant:
- Measuring length (mm)
- Resolution and accuracy (µm)
- Absolute or incremental output
- Interface
- Mounting tolerances: gap and alignment (mm)
- Readhead mass and cabling
- Environment: moisture, dust and temperature
Common mistakes to avoid
- Allowing condensation or liquid films on the scale
- Ignoring thermal expansion of the scale substrate
- Exceeding allowed gap tolerances
- Assuming optical-grade accuracy
KappaSense FREEe: frequently asked questions
Can you help replace KappaSense FREEe or source the original?
Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.
What is the KappaSense FREEe?
Capacitive absolute linear encoder with a passive 3 g read head and no moving cables; several heads can share one scale. Published series figures include linear speed 6 m/s. It is available through our supply network, and our engineers can confirm the right variant for your application.
Who makes the KappaSense FREEe?
The KappaSense FREEe is made by KappaSense (KappaSense Ltd.) available through our supply network. Send us your requirement for pricing, lead time, datasheets and CAD.
What is the linear speed of the KappaSense FREEe?
The published series maximum linear speed is 6 m/s. Individual models and sizes in the FREEe range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the KappaSense FREEe?
We can assess suitable replacement options. On published figures, Bogen ALS21 and Bogen IKS23 are options to assess from our supply network. An engineer confirms the fit against your application before recommending anything.
How does a capacitive linear encoder work?
The scale carries a pattern of electrodes and the readhead senses changes in capacitance as it moves along. Electronics convert the signal into position, either absolute or incremental. Because it uses electric fields, it is not affected by magnets and can tolerate wide mounting gaps.
Can multiple readheads share one capacitive scale?
Some capacitive designs allow several readheads to share one scale, each measuring its own position. This suits multi-carriage systems. Check that the specific encoder supports multiple heads, how close the heads may run to each other and that the controller interface can handle several position channels.
Further reading: How to select a linear encoder · Magnetic vs capacitive vs optical encoders · Encoders and feedback
Other capacitive linear encoder series
Engineer support
Need KappaSense FREEe or a complete system around it?
Tell us the part or application, quantity and timing. Our UK engineers will come back with the right product, pricing, lead time and delivery.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.
How it works
From enquiry to delivery
Send a part number or describe the application. Our engineers take it from there: the right product, a clear quotation, and delivery and support arranged.
- 01Tell us what you needSend a part number, or configure the application, quantities and timing.
- 02An engineer reviews itWe check the specification and find the original part, a checked equivalent or a complete axis.
- 03Receive your quotationProducts, pricing, lead time and compatibility notes in one reply.
- 04Order and deliveryWhen you are happy, the order is placed and delivery and after-sales support are arranged.