Updating…
STR
Vol. 01 · The Tank Monitoring Issue
For boaters & vanlifers
For OEMs & distributors
Radar-accurate tank levels, without the radar price tag.
STR. radar tank level sender for OEMs and distributors
Fig. 01STR1 (analogue) & STR2 (NMEA 2000) · radar tank level senders
Built to disrupt the tank sensing market.
Non contactApp calibrationRadar-grade accuracyMultiple simultaneous outputsLow profileDurable3-year warrantySealed housingUpdates via BluetoothPatent pendingMade in Slovenia
Non contactApp calibrationRadar-grade accuracyMultiple simultaneous outputsLow profileDurable3-year warrantySealed housingUpdates via BluetoothPatent pendingMade in Slovenia
The Thesis
The tank-sensing market hasn't moved in 30 years.
Floats stick. Probes corrode and seize. Capacitive senders drift. Distributors warehouse a dozen part numbers to cover every tank height and shape. STR has just two — analogue and digital.
OEMs build product lines around the limitations of legacy sensors, not the needs of the vessel or vehicle. STR is designed with both OEMs and users in mind: accurate, simple to install, wireless calibration, multiple simultaneous outputs, and wireless firmware updates.
One sender that fits every tank height, every material, every fluid*. Radar-grade accuracy at a price you can actually scale on.
*Tested on fresh, grey and waste water, plus fuel.
The first radar sensor that meets both your pricing and your quality expectations — and finally lets you standardize on a single platform across the catalog.
Chapter 02 · The Platform
Fourteen reasons partners choose
the STR radar tank level sender.
Designed from the radar chip up. Every feature engineered for the line, the warehouse, and the field — not just the bench.
№ 01 · Featured
The disruption
Incredible price–performance ratio.
Radar accuracy without radar-tier pricing. Built so OEMs and distributors don't have to choose between margin and quality anymore.
№ 02
Non-contact
Mounted externally on the tank top. Nothing inside the liquid — water, waste, or fuel.
№ 03
Calibration without a rig
Auto tank-height detection, then multi-point fine-tuning over Bluetooth in the Simarine Connect app — no external rigs, jigs, or factory tooling on your line.
№ 04
Universal outputs
All three analogue outputs at once on STR1 — 0–190 Ω, 240–33 Ω and 0–5 V — plus Bluetooth, drop-in compatible with any existing analogue gauge or monitor.
№ 05
Radar-grade accuracy
Millimeter-level resolution across the full range. No drift, no float stick, no foam confusion.
№ 06
Low profile
Slim, peel-and-stick form factor that fits into tight bays and under deck panels. Just 32.5 mm high and 62 mm in diameter.
№ 07
Durable
No moving parts, no float arms, no probes to foul. Engineered for the full life of the asset.
№ 08
3-year warranty
Every STR1 and STR2 ships with a full 3-year warranty — designed for OEM and distribution channels.
№ 09
Any tank, any fluid
150–2000 mm range, composite tanks direct or metal via the S5 metal tank adapter, and every fluid — fresh, grey and waste water, plus fuel.
№ 10
Made in Slovenia 🇸🇮
European-sourced components. Designed and manufactured in Slovenia, EU.
№ 11
Sealed housing — IP67
IP67-rated, splash-proof sealed enclosure built for marine, RV and off-grid environments — resists water, dust and daily field exposure.
№ 12
NMEA 2000 certification pending
STR2 publishes native NMEA 2000 PGN 127505 (Fluid Level) to any modern MFD. Formal NMEA 2000 certification is pending.
№ 13
Updates via Bluetooth
Firmware update in Simarine Connect app for new features and easy bug fixing.
№ 14
A defensible radar architecture
Patent-pending radar platform — exclusive in your catalog, not another commodity sender from the same three suppliers.
Field upgrade
Chapter 03 · The Field
Drop in.
Drop in.
Don't pull out.
The single biggest cost in tank-sender replacement isn't the sensor — it's pulling the old one out. Cutting access panels. Draining the tank. Sending a technician for a half-day job. STR removes the entire step.
-
Leave the old sender in place
Disconnect the wires from the old sensor and plug them into the STR using the supplied waterproof cable couplers. That's it. No extraction. No drain. No tank entry permit. The hardware that's been failing for years simply retires where it stands.
-
Bond STR to the tank top
Peel-and-stick mounting on composite tanks. S5 metal tank adapter for metal. Strong bond to any surface. Low profile fits even the tightest bay.
-
Calibrate over Bluetooth, wire to the existing gauge
The Simarine app handles tank geometry and calibration. STR's multiple simultaneous outputs match whatever gauge or monitor is already on the dash.
The commissioning tool
Commissioned, calibrated and updated from a phone.
Every STR is configured through the free Simarine Connect app — no proprietary programmers, no factory rigs, no service dongles. The same tool your line uses to commission a unit is the one your customer uses to update it in the field.
- i.Commission without a rig
Auto tank-height detection plus multi-point calibration in-app — no jigs or factory tooling on the line.
- ii.Configure over Bluetooth
Pair, name and set height, units and volume from a phone. No programming hardware to buy or maintain.
- iii.Field-updatable firmware
Push new features and fixes to units already shipped — no service cables, dongles or truck rolls.
- iv.Backup, restore & diagnostics
Save and restore device configs, read raw data and manage devices for fast, repeatable support.
- v.Lower support load
Customers self-serve setup and updates, so fewer commissioning questions reach your desk.
An intermission.
One platform.
Two products.
Zero compromises.
The first radar sensor that meets both your pricing and your quality expectations.
- i.Compatible with all gauges, monitors & systems
Bluetooth and all three analogue outputs simultaneously on STR1, or native NMEA 2000 on STR2. Drop STR into whatever dash or display you already ship.
- ii.Fast and easy installation
Peel-and-stick on composite tanks. Use an optional S5 metal tank adapter for metal tanks. Designed for the speed of your production line.
- iii.Calibration without a factory rig
Auto tank-height detection plus multi-point calibration in the Simarine Connect app. No external jigs, no factory tooling, no offline configuration station.
- iv.No configuration hardware required
Configure over Bluetooth from a phone. Your line keeps moving. Your warranty desk keeps its weekends.
- v.Firmware updates over Bluetooth
Push updates to sensors already in the field. No service cables, no proprietary dongles, no truck rolls.
- vi.3-year warranty
Every STR1 and STR2 is backed by a full 3-year warranty, designed for OEM channels and the lifecycles you actually ship.
- vii.Low profile · extra strong tape supplied to bond to any surface
Slim form factor fits tight production geometries. Bonds reliably to composite, metal, fibreglass, polyethylene.
- viii.Composite tanks direct · metal via S5 metal tank adapter
One sensor, two installation paths. The S5 metal tank adapter brings metal-tank fleets into the same platform.
- ix.Stock one sensor instead of many
Cut the SKU sprawl. Cut the part-number table on the wiring diagram.
- x.NMEA 2000 — certification pending
STR2 speaks native NMEA 2000 (PGN 127505) today; formal NMEA 2000 certification is pending. Ask us for the latest status and timeline.
Talk to OEM sales
One business-day reply, guaranteed.
Stock the whole shelf in two part numbers. Update them from a phone. Watch returns go quiet.
- i.Two part numbers, every customer
STR1 (analogue) or STR2 (NMEA) covers every tank height, material and fluid — inventory complexity drops from a dozen legacy senders to two.
- ii.Drop-in replacement for legacy senders
STR replaces floats, probes, capacitive units and ultrasonics from a single position on the catalog.
- iii.Universal outputs cover every gauge
All three analogue outputs at once (STR1), or native NMEA 2000 (STR2). No more gauge-compatibility lookups at the counter.
- iv.Updates & configuration via Bluetooth
No service kits, no programming dongles, no truck rolls. Customers self-update from the Simarine app.
- v.Reliable — no corrosion
Nothing inside the liquid. No probe to pit, no float to seize. The most common warranty reason just disappears.
- vi.3-year warranty
A full 3-year warranty on every STR1 and STR2 — fewer returns, fewer field calls, fewer end-of-month RMA spreadsheets to reconcile.
- vii.Patent pending technology
An exclusive platform in your catalog — not another commodity sender from the same three suppliers.
- viii.Made in Slovenia · EU supply chain
European components, predictable lead times, lower geopolitical risk on your forecast.
Become a distributor
Tell us your territory — we'll come back with terms.
Partnership Development Manager
mag. Luka Verdnik
Your direct line for OEM & distribution partnerships.
Chapter 06 · By the numbers
Why partners switch.
1Part covers every tank size & fluid
0Moving parts, no drift, no corrosion
3+Simultaneous output standards
🇸🇮Made in Slovenia · EU components
From the field
What the first installs say.
★★★★★
Now the work is done. I integrated three STR1 senders in my RV, wired to the Victron Cerbo GX — full overview from anywhere over the internet, or by Bluetooth in the Simarine Connect app.
★★★★★
I just installed the STR1 on my Nereide 2. I'm impressed by the mm accuracy and the ease of configuration. Finally an accurate fuel indication!
★★★★★
Just received it — works great!
Chapter 07 · How it compares
STR vs the rest.
The honest head-to-head — why legacy tank senders fall short, and where STR is built differently on every dimension that matters to your line and your shelf.
| Dimension | Simarine STR (radar) | Ultrasonic external | Capacitive / tube probes | Classic floats (resistive arm) |
|---|---|---|---|---|
| Contact with liquid | No | No | Yes (rod inside) | Yes (mechanical arm inside) |
| Moving parts | None | None | None | Yes — arm, pivot, float |
| Drift over time | None | Fine in clean air | Dielectric drifts with fluid changes | Float sticks, gummy fuel, corroded pivot |
| Foam / dirty liquid | Usually unaffected | Foam scatters | Fouled probe = wrong reading | Float fouls; reads "stuck" |
| Installation | Peel-and-stick, no penetration | Top-mount but needs clear air gap | Drill, seal, drop probe | Cut hole in top, screw flange, seal |
| Risk of leaks | None | None | Real | Real — gasket below liquid line |
| Tank material | Composite / GRP direct; metal via S5 metal tank adapter | Any | Any | Any (you're cutting it) |
| Works for any liquid | Yes — one part for all | Yes | Different probe per liquid | Often fluid-specific |
| Calibration | Auto tank height detection + up to 100 points in app | 2-point | 2-point usually | Mechanical / 2-point |
| Resolution | ≈ 7 mm regardless of tank height | ~1% | ~2% | ~5–10% of full scale |
| Outputs | STR1: all 3 analogue + BLE · STR2: NMEA 2000 + BLE | Voltage / NMEA | 4–20 mA, voltage | Resistive (0–190 Ω / 240–33 Ω) |
| Lifetime | No wear | 10+ yrs | 5–10 yrs, prone to fouling | 3–5 yrs, float fails |
| Price point | €69 / €99 excl. VAT · volume pricing on request | €200–400 | €100–250 | €15–40 cheap, €80+ marine |
Chapter 08 · Specifications
STR1 & STR2 — the
full technical picture.
Everything your engineering team needs to evaluate and integrate STR — measurement, outputs, electrical and physical specs for both variants, side by side.
| STR1 — Analogue | STR2 — NMEA 2000 | |
|---|---|---|
| Measurement | ||
| Principle | High-precision micro-radar (non-contact) | High-precision micro-radar (non-contact) |
| Supported Tank Height | 150–2000 mm | 150–2000 mm |
| Resolution | ≈ 7 mm | ≈ 7 mm |
| Dead zone | ≈ 40 mm from radar face | ≈ 40 mm from radar face |
| Update rate | 1 Hz | 0.5 Hz (NMEA 2000 bus) |
| Tanks & liquids | ||
| Liquids | Fresh water · Grey water · Waste water · Fuel | Fresh water · Grey water · Waste water · Fuel |
| Tank material | Composite / GRP — metal via S5 metal tank adapter | Composite / GRP — metal via S5 metal tank adapter |
| Maximum wall thickness | 10 mm | 10 mm |
| Outputs to your gauge or display | ||
| Analogue outputs | 0–190 Ω · 240–33 Ω · 0–5 V all three available simultaneously | Not available |
| NMEA 2000 | Not available | Native PGN 127505 — Fluid Level |
| Bluetooth app (setup & monitoring) | Simarine Connect app | Simarine Connect app |
| Firmware updates | Over Bluetooth — Simarine Connect app | Over Bluetooth — Simarine Connect app |
| Simarine Pico | Yes | No |
| Electrical | ||
| Supply voltage | 8–35 V DC | 8–35 V DC |
| Current draw | ≈ 14–20 mA @ 12 V | ≈ 14–20 mA @ 12 V |
| Physical & origin | ||
| Profile | Low-profile — ≈ 32.5 mm tall | Low-profile — ≈ 32.5 mm tall |
| Mounting | Top-mount, peel-and-stick (external) | Top-mount, peel-and-stick (external) |
| Ingress protection | IP67 — splash-proof | IP67 — splash-proof |
| Warranty | 3-year warranty | 3-year warranty |
| Made in | 🇸🇮 Slovenia | 🇸🇮 Slovenia |
Chapter 09 · The documentation
Specs, drawings
& integration docs.
Everything your engineering and service teams need to evaluate, integrate and support STR. Manuals and guides download directly; datasheets, CAD/STEP and the full integration pack are sent on request while we finalise the public OEM library.
Manual
STR1 Manual
Install, wiring colours and the 0–190 Ω / 240–33 Ω / 0–5 V analogue outputs.
Manual
STR2 Manual
Network wiring, BLE setup and NMEA 2000 PGN 127505 configuration.
Quick guide
STR Quick Guide
One-page setup to get STR1 or STR2 installed and reading in minutes.
Quick guide
S5 Metal Tank Adapter Guide
Mounting the S5 metal tank adapter on metal tanks — surface prep, alignment and bonding.
App guide
App Setup Instructions
Step-by-step Simarine Connect app setup for STR1 & STR2 — pairing, first-time setup, calibration and settings.
Chapter 10 · The conversation
Two ways
to get started.
We're ramping production now, so exact lead times still shift week to week. Early partners get first allocation — the fastest way to secure yours is a direct line to sales.
Path one
Request an evaluation sample
Tell us the application — boat, RV, off-grid, industrial — and the tank materials you're working with. We'll ship a unit you can install, calibrate and stress-test on your own bench.
Request a sampleLuka Verdnik · Sales · one business-day reply (CET)
Path two
Book a call with sales
30 minutes with the team that built STR. We'll walk through pricing, outputs, your platform, your service network, and the path from sample to ship-in-volume.
Book a callLuka Verdnik · Sales · one business-day reply (CET)