CALCULATORS / SENSORS AND INSTRUMENTATION

Load-cell readout sizing calculator

Linear load-cell sensitivity in V/V at rated load; offset omitted.

sensors-load-cell.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	outputmV
	4
	5

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

load within rating40.00 N✓ passes

BASELINE INPUTS

ratedLoad100 Nload40 Nsensitivity0.002 excitation5 V

CALCULATED

output4 mV

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Load-cell readout sizing
# Scope: Linear load-cell sensitivity in V/V at rated load; offset omitted.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

ratedLoad = 100 N
load = 40 N
sensitivity = 0.002
excitation = 5 V

output := sensitivity*excitation*load/ratedLoad [mV]

check load within rating: load <= ratedLoad

scenario alternative: ratedLoad = 80 N

Calculated from your source · not saved

Baseline · Baseline

load within rating40.00 N ✓ passes

alternative · alternative

load within rating40.00 N ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

output: output = sensitivity*excitation*load/ratedLoad [mV]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

rated load: 100 N
load: 40 N
sensitivity: 0.002
excitation: 5 V

Calculated

output: 4 mV

Assumptions and limits

Linear load-cell sensitivity in V/V at rated load; offset omitted.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Load-cell readout sizing. Inputs: rated sensitivity; excitation; force span; ADC chain. Outputs: signal span; nominal force resolution. Model scope: Measurement chains with explicit noise, bandwidth and calibration. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: rated sensitivity, excitation, force span, ADC chain
Outputs: signal span, nominal force resolution
Modes: calculate, compare, sweep
Drawing: Signal-chain and error plots

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS