Hand-Arm Vibration A(8) Daily Exposure Calculator

Normalize vector-summed already frequency-weighted hand-arm RMS acceleration over exactly eight reference hours (caller reference must be 8); no raw-signal filtering, exposure limit or medical/safe-work recommendation.

Description

A(8) normalizes the squared vector sum of already weighted hand-arm acceleration to eight hours.

A(8) normalizes the squared vector sum of already weighted hand-arm acceleration to eight hours. Raw axes need prior frequency weighting.^[1]

Enter aligned nonempty three-axis rows/nonnegative hours totaling≤24 and caller reference exactly 8. Return equivalent acceleration and total exposure hours.

When to use Hand-Arm Vibration A(8) Daily Exposure Calculator

Use Hand-Arm Vibration A(8) Daily Exposure Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No filtering, exposure limit or medical/safe-work recommendation is supplied.

Prepare measured task, body, furniture or already weighted exposure records. Supply independently verified caller policies, tables and comparison limits with matching units and conditions.

How to use Hand-Arm Vibration A(8) Daily Exposure Calculator and understand its results

Prepare measured task, body, furniture or already weighted exposure records. Supply independently verified caller policies, tables and comparison limits with matching units and conditions.
Enter frequencyWeightedAccelerationAxesMPerS2, representedExposureHours, callerReferenceHours using the field table and calculation rules, then run the tool.
Read eightHourEquivalentAccelerationMPerS2, totalExposureHours. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
frequencyWeightedAccelerationAxesMPerS2	Frequency weighted acceleration axes m per s2	list of list of number	Required
representedExposureHours	Represented exposure hours	list of number	Required
callerReferenceHours	Caller reference hours	number	Required

Enter aligned nonempty three-axis rows/nonnegative hours totaling≤24 and caller reference exactly 8. Return equivalent acceleration and total exposure hours.

A8=sqrt(sum((ax²+ay²+az²)×hours/8))

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
eightHourEquivalentAccelerationMPerS2	Eight hour equivalent acceleration m per s2	number
totalExposureHours	Total exposure hours	number

json

{
  "input": {
    "frequencyWeightedAccelerationAxesMPerS2": [
      [
        3,
        4,
        0
      ],
      [
        0,
        0,
        2
      ]
    ],
    "representedExposureHours": [
      2,
      2
    ],
    "callerReferenceHours": 8
  },
  "output": {
    "eightHourEquivalentAccelerationMPerS2": 2.692582403567252,
    "totalExposureHours": 4
  }
}

Limitations and assumptions

No filtering, exposure limit or medical/safe-work recommendation is supplied.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Matrices are limited to 128 rows and 128 entries per row. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use HAV Points per Hour Trigger Time Calculator: Vibration points can be inverted into remaining exposure time under explicit caller calibration. A negative budget margin remains visible. For a complementary task, use Seat Effective Amplitude Transmissibility Factor Lookup: Seat effective amplitude transmissibility compares time-weighted seat and floor RMS measurements. Both histories must share weighting conventions.

References

Hand-Arm Vibration A(8) Daily Exposure Calculator — tool.io

Similar or alternative tools

HAV Points per Hour Trigger Time Calculator
Vibration points can be inverted into remaining exposure time under explicit caller calibration. A negative budget margin remains visible.
Seat Effective Amplitude Transmissibility Factor Lookup
Seat effective amplitude transmissibility compares time-weighted seat and floor RMS measurements. Both histories must share weighting conventions.