Documentation sections

Sensor Accuracy Budget

POSThttps://rftools.io/api/py/v1/calculate

Slug sensor-accuracy-budget. Calculate total sensor error using RSS and worst-case methods. Analyze offset, gain, nonlinearity, resolution, and temperature drift contributions.

Inputs

Send every one of these in inputs, in the units shown. Most are required: a call without one is refused (400) and costs nothing; one the calculator can do without takes the default shown. An input outside its range is still computed and flagged in the provenance.

Inputs of sensor-accuracy-budget
Name	Unit	Range	Default	Description
offsetErrornumber	% FS	at least 0	0.1	Offset Error
gainErrornumber	% FS	at least 0	0.2	Gain/Sensitivity Error
nonlinearitynumber	% FS	at least 0	0.1	Nonlinearity
resolutionnumber	% FS	at least 0	0.05	Resolution Error
tempDriftnumber	% FS/°C	at least 0	0.005	Temp Drift
tempRangenumber	°C	at least 0	40	Temperature Range
errorTermsnumber	none	0 … 6	0	How many further error terms the budget includes (0–6)
term1Errornumber	% FS	0 … 100	0	A further error, such as hysteresis, repeatability, long-term stability or the ADC reference
term2Errornumber	% FS	0 … 100	0	A further error, such as hysteresis, repeatability, long-term stability or the ADC reference
term3Errornumber	% FS	0 … 100	0	A further error, such as hysteresis, repeatability, long-term stability or the ADC reference
term4Errornumber	% FS	0 … 100	0	A further error, such as hysteresis, repeatability, long-term stability or the ADC reference
term5Errornumber	% FS	0 … 100	0	A further error, such as hysteresis, repeatability, long-term stability or the ADC reference
term6Errornumber	% FS	0 … 100	0	A further error, such as hysteresis, repeatability, long-term stability or the ADC reference

Outputs

Returned in values, by key. A value that is unbounded or undefined is null.

Outputs of sensor-accuracy-budget
Field	Unit	Description
tempError	% FS	Temperature Error
totalRssheadline	% FS	Total Accuracy (RSS)
totalWorstCase	% FS	Total Accuracy (Worst Case)

Calling it

Calculate: one call, the request and response in full, and its errors.
Batch: this calculator with others, or a sweep, in one request.
Solve for a target: the value of one input that brings an output to a target.

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "sensor-accuracy-budget",
    "inputs": {
      "offsetError": 0.1,
      "gainError": 0.2,
      "nonlinearity": 0.1,
      "resolution": 0.05,
      "tempDrift": 0.005,
      "tempRange": 40,
      "errorTerms": 0,
      "term1Error": 0,
      "term2Error": 0,
      "term3Error": 0,
      "term4Error": 0,
      "term5Error": 0,
      "term6Error": 0
    }
  }'

import rftools

client = rftools.Client()  # reads RFTOOLS_API_KEY, or the key `rftools login` saved

result = client.calculate("sensor-accuracy-budget", {
    "offsetError": 0.1,
    "gainError": 0.2,
    "nonlinearity": 0.1,
    "resolution": 0.05,
    "tempDrift": 0.005,
    "tempRange": 40,
    "errorTerms": 0,
    "term1Error": 0,
    "term2Error": 0,
    "term3Error": 0,
    "term4Error": 0,
    "term5Error": 0,
    "term6Error": 0,
})
print(result.values)
print(result.warnings, result.provenance.formula_ref)

const response = await fetch("https://rftools.io/api/py/v1/calculate", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.RFTOOLS_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "slug": "sensor-accuracy-budget",
    "inputs": {
      "offsetError": 0.1,
      "gainError": 0.2,
      "nonlinearity": 0.1,
      "resolution": 0.05,
      "tempDrift": 0.005,
      "tempRange": 40,
      "errorTerms": 0,
      "term1Error": 0,
      "term2Error": 0,
      "term3Error": 0,
      "term4Error": 0,
      "term5Error": 0,
      "term6Error": 0
    }
  }),
});
console.log(response.status, await response.json());

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	body := []byte(`{
	  "slug": "sensor-accuracy-budget",
	  "inputs": {
	    "offsetError": 0.1,
	    "gainError": 0.2,
	    "nonlinearity": 0.1,
	    "resolution": 0.05,
	    "tempDrift": 0.005,
	    "tempRange": 40,
	    "errorTerms": 0,
	    "term1Error": 0,
	    "term2Error": 0,
	    "term3Error": 0,
	    "term4Error": 0,
	    "term5Error": 0,
	    "term6Error": 0
	  }
	}`)
	req, err := http.NewRequest("POST", "https://rftools.io/api/py/v1/calculate", bytes.NewReader(body))
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-API-Key", os.Getenv("RFTOOLS_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

application/json

{
  "slug": "sensor-accuracy-budget",
  "values": {
    "tempError": 0.2,
    "totalRss": 0.32015621187164245,
    "totalWorstCase": 0.65
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:sensor-accuracy-budget",
    "version": "api@3f2c1a9b04de",
    "formulaRef": null,
    "assumptions": [],
    "validRange": {
      "status": "inside",
      "bounds": {
        "offsetError": {
          "min": 0,
          "max": null,
          "unit": "% FS"
        },
        "gainError": {
          "min": 0,
          "max": null,
          "unit": "% FS"
        },
        "nonlinearity": {
          "min": 0,
          "max": null,
          "unit": "% FS"
        },
        "resolution": {
          "min": 0,
          "max": null,
          "unit": "% FS"
        },
        "tempDrift": {
          "min": 0,
          "max": null,
          "unit": "% FS/°C"
        },
        "tempRange": {
          "min": 0,
          "max": null,
          "unit": "°C"
        },
        "errorTerms": {
          "min": 0,
          "max": 6,
          "unit": ""
        },
        "term1Error": {
          "min": 0,
          "max": 100,
          "unit": "% FS"
        },
        "term2Error": {
          "min": 0,
          "max": 100,
          "unit": "% FS"
        },
        "term3Error": {
          "min": 0,
          "max": 100,
          "unit": "% FS"
        },
        "term4Error": {
          "min": 0,
          "max": 100,
          "unit": "% FS"
        },
        "term5Error": {
          "min": 0,
          "max": 100,
          "unit": "% FS"
        },
        "term6Error": {
          "min": 0,
          "max": 100,
          "unit": "% FS"
        }
      },
      "outside": [],
      "model": null
    },
    "computedAt": "2026-09-24T14:05:11.003Z",
    "inputs": {
      "offsetError": 0.1,
      "gainError": 0.2,
      "nonlinearity": 0.1,
      "resolution": 0.05,
      "tempDrift": 0.005,
      "tempRange": 40,
      "errorTerms": 0,
      "term1Error": 0,
      "term2Error": 0,
      "term3Error": 0,
      "term4Error": 0,
      "term5Error": 0,
      "term6Error": 0
    },
    "seed": null,
    "elapsedSeconds": 0.003
  }
}

{
  "detail": [
    {
      "type": "float_parsing",
      "loc": [
        "body",
        "inputs",
        "offsetError"
      ],
      "msg": "Input should be a valid number, unable to parse string as a number",
      "input": "abc"
    }
  ]
}

An input sent as text. Nothing was counted.

{
  "detail": "More than 120 requests in 60 seconds from this address.",
  "errorKind": "rate_limited",
  "limit": 120,
  "windowSeconds": 60,
  "upgradeUrl": "https://rftools.io/pricing/"
}

Too many requests in a minute, with Retry-After.

Same inputs on the calculator pageSensor Accuracy Budget, at these values