Short answer
Hardware is the only line that does not repeat. SIM subscriptions are billed monthly and a dual-SIM device means two of them. Installation labour is billed per device. Calibration is billed per tank, and a fuel-blend change triggers the whole calibration again. Those recurring lines usually pass the hardware within the first year.
Key takeaways
- A dual-SIM device carries two subscriptions, not one, our Jointech JT701 listing is dual SIM, so the monthly line doubles per unit.
- Roaming versus local matters for a cross-border asset, because the GSMA register shows Saudi operators running non-overlapping low-power technologies.
- Calibration is per tank, not per fleet: Teltonika documents 5–10% fill increments with about 30 seconds of settling at each point.
- A fuel-blend change re-triggers the whole calibration, measured permittivity is 2.2 for diesel against 3.3 for biodiesel, a 50% shift.
- Count every recurring line per device, per tank and per month before comparing two hardware quotations at all.
01The quotation is one line of many
A hardware quotation arrives as a clean number: so many devices at so much each. That number has a property none of the other cost lines share, it happens once. Everything underneath it is counted per device, per tank, per month or per event, which means it scales with the fleet and it keeps scaling after the invoice is paid. That structural difference is why two deployments with identical hardware quotations can end the first year far apart. The lines that produce the gap are not exotic: cellular subscriptions, installation labour, calibration effort, and the recalibration events that a change in the operating environment forces. None of them is hidden and none of them requires a specialist to estimate. They are simply absent from the document the buyer is reading, because a hardware supplier quotes hardware. Build the other lines yourself, before choosing between suppliers rather than after.
02SIM subscriptions, and the dual-SIM multiplier
A connected device needs a subscription, and a device with two SIM slots needs two. Our Jointech JT701 listing is dual SIM, which is a genuine resilience feature and also a doubling of the monthly line for every unit deployed. That multiplication is easy to miss because the hardware specification presents dual SIM as a benefit, which it is, without presenting it as a recurring cost, which it also is. The arithmetic is simple and it is worth doing explicitly before signing: one subscription per slot, per device, per month, for the life of the deployment. Then ask whether the second SIM is actually needed on every asset or only on the subset that crosses a coverage boundary, because a resilience feature bought fleet-wide when a quarter of the fleet needs it is a recurring line you pay four times over for one benefit.
03Roaming or local, for a cross-border asset
The choice between a roaming subscription and a local one is a cost line and a coverage decision at the same time. It matters most where the technology available differs by network. The GSMA commercial launch register, whose data was last updated in November 2025, lists the Saudi operators with non-overlapping low-power technologies: Mobily with LTE-M, and STC with NB-IoT and no LTE-M listed. Zain KSA does not appear in that commercial register; the documented activity is an NB-IoT trial announced in October 2017. So for a low-power device the network choice is narrow within one country, and a roaming agreement that assumes the technology exists on the visited network can produce an asset that attaches nowhere. Price the subscription against the actual technology in the device and the actual route the asset travels, and ask the question before the device is sealed into a trailer.
04Installation labour is counted per device
Installation is billed per unit, which makes it the line that scales most directly with fleet size, and it varies enormously by mounting position. Our catalogue shows why: the Teltonika FMC003 listing is IP41 with a 67-gram body designed to sit behind a dashboard, while the OMNICOMM fuel level sensor listing is IP68 with a top-mount standard thread that goes into a tank. Those two jobs are not comparable. One is a cabin fit with a plug and a cable route; the other is work on a fuel tank, which brings drainage, sealing and a return to service. The catalogue also lists a one-metre cable, extendable, on the OMNICOMM sensor, and cable routing is labour rather than parts. When comparing suppliers, ask for a labour estimate per mounting position rather than per device type, because the position and not the model determines how long an installer stands there.
05Calibration is per tank, and it takes real time
Calibration is the cost line most often left out entirely, and it is measurable rather than vague. Teltonika documents the procedure for an analog fuel sensor: fill the tank in 5 to 10 per cent increments and allow roughly 30 seconds of settling at each point, then fit the litres-versus-voltage table into cubic coefficients a0, a1, a2 and a3. Count the points that implies. At 5 per cent increments the technician takes about twenty readings per tank, each with a settling wait, and every one of them happens with fuel actually being added. That is an hour of vehicle downtime and a tank of fuel moved, per tank, before a single number reaches the platform. Teltonika also documents a diagnostic that can send you back to the start: the voltages must change consistently, and up-and-down values mean a fault to find before continuing.
06Recalibration is an event, and something triggers it
The calibration cost is not a one-off if the fuel changes. A capacitive probe infers level from the permittivity of what surrounds it, and that property is not the same across fuels. Measured at 21.0 ± 0.1 °C, over 1 Hz to 1×10⁶ Hz at 0.2 V, the dielectric constant of diesel is 2.2 and of biodiesel 3.3, a 50 per cent shift in the exact quantity the sensor is measuring. A tank calibrated on one blend and then filled with another is reporting against a curve that no longer describes its contents, and the correction is not a software setting but the whole twenty-point procedure again, per tank. So a fuel-blend change is a budget event. Ask whether the fuel supply is committed for the deployment period, and if it is not, count at least one recalibration cycle per tank into the first-year figure rather than discovering it as an overrun.
07Building the first-year figure
Assemble the number in the units each line is actually counted in, and the shape becomes obvious. Hardware is a count of devices, once. SIM subscriptions are a count of slots multiplied by devices multiplied by twelve months, and a dual-SIM device such as the JT701 listing puts a two in that product. Installation is a count of devices, priced by mounting position rather than by model. Calibration is a count of tanks, each at roughly twenty settling points. Recalibration is a count of expected blend or configuration changes, each costing a full calibration again. Only the first of those five is a single event. That is the whole argument: the recurring side is multiplied by fleet size and by months, and the one-off side is not, so on any deployment large enough to be worth managing the recurring lines pass the hardware quotation well inside the first year.
| Cost line | Counted per | Repeats? |
|---|---|---|
| Hardware | Device | No, once |
| SIM subscription | SIM slot × device × month | Yes, monthly |
| Second SIM on a dual-SIM device | Slot × device × month | Yes, doubles the line |
| Installation labour | Device, priced by mounting position | On replacement only |
| Calibration | Tank, ~20 settling points at 5% increments | On commissioning |
| Recalibration | Blend or configuration change event | Yes, full procedure again |
| Platform subscription | Device × month | Yes, monthly |
Figures and sources
- Jointech JT701 SIM configuration, the line that doubles the monthly subscription per unit: dual SIM; GSM / 3G; 15,000 mAh Li-ion (Source: ENTEK.AI product catalogue, as of 2026-08-31)
- Teltonika FMC003 physical properties that set the cabin installation labour: 67 g; 65 × 56.6 × 20.3 mm; IP41; 10 – 30 V DC (Source: ENTEK.AI product catalogue, as of 2026-08-31)
- OMNICOMM sensor installation method and cable length, the tank-side labour line: top-mount, standard thread; 1 m cable (extendable); IP68 (Source: ENTEK.AI product catalogue, as of 2026-08-31)
- Teltonika documented calibration procedure and the polynomial it produces: 5–10% tank increments, ~30 s settling; yields cubic coefficients a0, a1, a2, a3 (Source: Teltonika Telematics Wiki, Analog Fuel Sensor, as of 2026-08-31)
- Teltonika monotonicity diagnostic that can restart the calibration: voltages must change consistently; up-and-down values mean a fault to find before continuing (Source: Teltonika Telematics Wiki, Analog Fuel Sensor, as of 2026-08-31)
- Measured room-temperature dielectric constants of diesel versus biodiesel, the recalibration trigger: diesel 2.2, biodiesel 3.3 (a 50% shift) (Source: Sensors (MDPI), PMC8588433, Electrical characterization of biodiesel–diesel blends, as of 2026-08-31)
- Controlled conditions under which those permittivity values were measured: 1 Hz to 1×10⁶ Hz, 0.2 V, at 21.0 ± 0.1 °C (Source: Sensors (MDPI), PMC8588433, as of 2026-08-31)
- Saudi operator low-power technology split, what a roaming subscription must actually find: Mobily: LTE-M; STC: NB-IoT (no LTE-M listed); Zain KSA absent from the commercial register (Source: GSMA Mobile IoT Commercial Launches (data last updated November 2025), as of 2026-08-31)
Questions
Why does a dual-SIM device cost more every month?
Because each slot needs its own subscription. Our Jointech JT701 listing is dual SIM, so the monthly line is two subscriptions per unit rather than one. Decide whether the resilience is needed on the whole fleet or only on the assets that cross a coverage boundary.
How long does calibrating one tank actually take?
Teltonika documents 5–10% fill increments with about 30 seconds of settling at each point. At 5% increments that is roughly twenty readings per tank, each while fuel is being added, so about an hour of downtime and a tank of fuel moved before the first number arrives.
What makes a recalibration necessary?
A change in the fuel itself. A capacitive probe reads permittivity, and measured values are 2.2 for diesel against 3.3 for biodiesel, a 50% shift in the quantity being measured. The old curve no longer describes the contents, and the fix is the whole procedure again.
Does installation labour differ much between devices?
It differs by mounting position rather than by model. The FMC003 listing is a 67-gram IP41 unit for a cabin; the OMNICOMM listing is an IP68 top-mount sensor that goes into a tank with a one-metre cable. Ask for labour per position, not per device type.