First identify the quantity behind dB(A)
A-weighted sound power level, LWA, describes sound emitted by the source under specified operating conditions. A-weighted emission sound pressure level, LpA, describes the machine’s contribution at specified positions under a declared test method. That method excludes or corrects background and environmental contributions.
These quantities cannot be ranked against each other numerically. A quotation giving LWA and another giving LpA do not establish which granulator is quieter, even if both use dB(A). There is no fixed conversion to apply. Ask the supplier to name the quantity before putting the figures in a comparison sheet. The glossary in the NOMAD noise reporting guide explains this distinction.
Match the cutting job and the equipment included
Keep idle operation and loaded cutting in separate rows. An idle figure cannot answer the same purchasing question as a figure measured while processing scrap. Record the material and load, machine configuration and operating parameters alongside each result, so a favourable number does not lose its context.
Also identify which feeding, discharge and blower equipment was running. An enclosure around the cutting chamber does not necessarily enclose the material-handling line. If your proposed installation includes those auxiliaries, a figure covering only the granulator leaves part of your noise question unanswered.
The RHONG RG-26GQ soundproof granulator is an enclosed arrangement. The product name describes that arrangement; it does not establish silence or a measured noise level. Compare the quoted configuration and its noise information rather than treating the name as a performance result.
Read the test conditions with the result
Keep the test conditions with the declared result. HSE’s manufacturer guidance identifies the method, operating conditions and uncertainty as essential context.
| Detail | What it tells you |
|---|---|
| Quantity and method | Whether the values describe the same acoustic quantity and a comparable test. |
| Measurement position | Where a pressure value applies, with its distance and test-environment information. |
| Operating state | The scrap, loading and machine parameters used, with idling and cutting distinguished. |
| Equipment boundary | Which feeding, discharge, blower and collection equipment operated during the test. |
| Result and uncertainty | The reported metric, observation period, corrections and associated uncertainty. |
Missing details, or differences that prevent a like-for-like comparison, leave the ranking unresolved. Read a small numerical difference alongside the reported uncertainty. Different machine configurations can still be compared when their test basis and intended work are sufficiently aligned.
Relate the declaration to your factory layout
A microphone reading in a working factory can include room effects and other sound sources. Its result depends on the position and distance, reflections and absorption, as Brüel & Kjær explains. It is not automatically the machine’s declared emission sound pressure level.
Use the proposed operator locations and the beside-the-press or central granulation layout to frame the installation discussion. Comparable emission data helps equipment selection, but employee daily exposure also depends on other workplace sources, where people work and how long they spend there. A catalogue noise figure alone cannot settle that assessment.