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Check bridge output, excitation burden and ideal analog scaling before requesting a conditioner.
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Ideal linear zero-offset mapping, not measured hardware performance.
Aggregate excitation is the sum across bridges. It is not the amplifier’s DC input-supply current.
Matched parallel bridges produce one total; their mV/V signals are not multiplied by cell count. A summing/trim arrangement still needs review.
Model qualification remains open: datasheet, excitation limit, offset, pinout, filtering, isolation and calibration.
Default example: four matched 350Ω bridges, 2mV/V, 5V excitation, 50% equal fractional load. Ideal zero-offset arithmetic excludes cable/trim losses, unequal loading, drift and noise. Calculation ranges are not product ratings.
METHOD / INPUTS TO A MODEL REVIEW
This model is for complete strain-gauge bridges. Half/quarter-bridge completion, already amplified sensors and piezoelectric inputs require a different interface review.
Use the signal calculation to define the differential input magnitude. Use the resistance/current calculation to define the bridge drive burden. Neither one establishes the input common-mode range, accuracy, noise floor or mechanical load capacity.
V_FS (mV) = S (mV/V) × V_exc (V)
V_signal (mV) = V_FS × load (%) / 100
R_parallel = R_input / N
I_each (mA) = 1000 × V_exc / R_input
I_total = N × I_each
These are ideal, zero-offset relationships. For a matched parallel installation the chosen load fraction applies equally to each cell. An actual junction box may introduce trimming and cable effects that this model does not solve.
| Input / result | Meaning | What to obtain |
|---|---|---|
| Sensitivity, mV/V | Rated differential signal per volt of excitation | Specific sensor calibration/datasheet, positive magnitude |
| Excitation, V | Assumed voltage at the bridge | Permitted sensor excitation and measured cable-end conditions |
| Input resistance, Ω | Resistance seen by the excitation source | Excitation-terminal input value, including relevant tolerances |
| Driver/input limits | Optional user-entered constraints | Exact amplifier rating at the chosen excitation and configuration |
| Architecture | Resistance seen by one driver | Driver current | Selection consequence |
|---|---|---|---|
| One bridge | R_input | I_each | Confirm one sensor and its receiver/interface. |
| N matched parallel bridges | R_input / N | N × I_each | One summed signal; inspect excitation capacity, trimming and matched-cell behavior. |
| N independent channels | R_input per channel | I_each per channel | Separate readings require actual separate channels. Review aggregate power and synchronization separately. |
A nominal “350Ω” label alone may refer to a different resistance than the excitation input. Incorrectly using output resistance can produce an incorrect current estimate. Use the actual input-resistance specification and allow for its tolerance.
For a single total, compare the summing-box requirements. For separate corner-force values, review independent fieldbus channels. A particular protocol or hardware variant still needs confirmation.
| Requested output | Defined x range | Ideal mapping | At x = 0.5 |
|---|---|---|---|
| 0–10V | 0 to 1 | 10 × x V | 5V |
| ±10V | −1 to 1 | 10 × x V | 5V |
| 4–20mA | 0 to 1 | 4 + 16 × x mA | 12mA |
| USB / fieldbus | Model-specific | No analog output computed | Units/register/command mapping to confirm |
For a 10mV positive rated signal mapped to 10V, the ideal gain is 10 / 0.010 = 1,000 V/V. A bipolar request maps −10mV to −10V and +10mV to +10V, so its span ratio is also 1,000 V/V. A 4–20mA mapping instead has an offset and current span; it is not a voltage gain.
Negative input with a unipolar preset is shown as outside mapping. This tool does not claim the real transmitter will clamp, extrapolate or enter a fault state. For that behavior, review the selected analog load cell conditioner and PLC input together.
HYPOTHETICAL WORKED EXAMPLES / NOT PHYSICAL TESTS
| Planning example | Inputs | Bridge and drive result | Receiver request |
|---|---|---|---|
| One PLC channel | 1 × 350Ω; 2mV/V; 5V; 50% load | 10mV rated; 5mV at chosen load; 14.2857mA excitation | 0–10V → ideal 5V |
| Four-cell total | 4 × 350Ω parallel; 2mV/V; 5V; equal 50% load | 87.5Ω parallel; 10mV rated; 57.1429mA shared excitation | 4–20mA → ideal 12mA |
| Four independent channels | 4 × 700Ω; 3mV/V; 10V; −50% per channel | 30mV rated; −15mV at load; 14.2857mA per channel; 57.1429mA aggregate | ±10V → ideal −5V per channel |
Reproduce these inputs in the tool, then enter a candidate model’s actual limits. For the four-cell total, a shared 50mA limit is exceeded. For the independent example, a 20mA per-channel limit contains the nominal current, but a 25mV input-magnitude limit is exceeded. A within-limit arithmetic result still leaves wiring, common-mode range, offset, tolerances and calibration unresolved.
Use excitation at the bridge. Lead and trim drops are excluded; four-wire and remote-sense installations need their own connection review. A model cannot be selected using a wire color convention alone.
Review pinout and connector requirements ↗Rated mV is a differential magnitude. Zero balance, tare/dead load, common-mode voltage and overload transients can consume different input margins. The optional magnitude limit does not check those effects.
Plan electrical and physical acceptance ↗Increasing gain does not create more usable signal information. Ask for performance at the required filter/rate and consider extra channels, junction hardware, software, calibration and installation work in the quote.
Compare family and interface decisions ↗PRIMARY REFERENCES / REVIEWED 31 OCTOBER 2026
The ratiometric definition is supported by the PCB handbook. Resistance/current and linear mapping equations are elementary circuit and scaling derivations. Manufacturer examples describe their own products; they do not establish MT-AMP compatibility, stock or test performance.
Ratiometric output: rated mV/V multiplied by excitation gives the nominal rated mV signal.
Context for a bridge excitation source and a conditioner between the raw sensor signal and the receiver.
An original product example of a stated multi-bridge excitation capability and selectable analog ranges. Original-model facts do not qualify MT-AMP products.
Method version 1 · Reviewed . No measured sensor dataset is used. Field performance and model approval remain separate.
Not in this matched-bridge, equal fractional-load model. The signal remains the same nominal mV/V while input resistance falls and excitation current rises. Unequal sensitivity, resistance, trim or loading needs a separate summing-system review.
Use the complete sensor input resistance across its excitation terminals at the stated conditions. Output resistance across signal terminals and individual strain-gauge resistance are different quantities. Obtain the input value from the sensor datasheet.
No. Enter an excitation voltage permitted by the specific sensor datasheet. The calculator range is a computational range, not a safe operating recommendation. Bridge heating, cable loss and the conditioner driver must also be reviewed.
That preset maps zero load to 4mA and positive rated load to 20mA. Negative load is outside its defined range. A tension/compression system can use another agreed zero/span map, such as a bipolar voltage request; actual clipping or fault behavior is not predicted.
No. V/V gain is shown only for voltage presets. The current preset is a requested linear mapping with a 16mA span. It does not establish active/passive loop compatibility, burden resistance or compliance voltage.
No. It calculates an ideal bridge and mapping budget. Exact input common-mode range, offset headroom, excitation regulation, wiring, noise, filtering, software and replacement compatibility require a model-specific engineering review.
No. It is the sum of current delivered to the modeled bridges at the selected excitation voltage. Conditioner electronics and power-conversion behavior are excluded. Independent channel driver limits apply per channel, not to the aggregate alone.
A share link contains the bounded engineering inputs only. A valid RFQ handoff recomputes those inputs and includes the planning values and limit-review states alongside your form entries. Contact information is entered separately on the inquiry page.
Download the blank interface review workbook ↗
The workbook provides a manual path without JavaScript. It is a planning document and blank acceptance worksheet, not a released product datasheet or calibration certificate.
Use the result’s RFQ or email action to include its inputs, calculated values and limit checks. Add your sensor datasheet, connector pinout, controller model and required measurement speed for the engineering review.
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