{"product_id":"tools-of-the-trade-fluid-mechanics-excel-calculator","title":"Tools of the Trade: Fluid Mechanics Excel Calculator","description":"\u003ch3 data-start=\"366\" data-end=\"429\"\u003eCorrecting LEV Measurements for Non-Standard Air Conditions\u003c\/h3\u003e\n\u003cp data-start=\"431\" data-end=\"730\"\u003eIn most LEV work, calculations are taught and carried out using \u003cstrong data-start=\"495\" data-end=\"522\"\u003estandard air conditions\u003c\/strong\u003e — an air density of \u003cstrong data-start=\"543\" data-end=\"556\"\u003e1.2 kg\/m³\u003c\/strong\u003e, equivalent to dry air at \u003cstrong data-start=\"583\" data-end=\"596\"\u003e1013 mbar\u003c\/strong\u003e and \u003cstrong data-start=\"601\" data-end=\"610\"\u003e20 °C\u003c\/strong\u003e. This assumption underpins much of the LEV maths taught in BOHS qualifications and referenced in engineering standards.\u003c\/p\u003e\n\u003cp data-start=\"732\" data-end=\"795\"\u003eHowever, not all LEV systems operate under standard conditions.\u003c\/p\u003e\n\u003cp data-start=\"797\" data-end=\"1156\"\u003eDuring a COSHH Regulation 9 Thorough Examination and Test (TExT), practitioners regularly encounter \u003cstrong data-start=\"897\" data-end=\"917\"\u003enon-standard air\u003c\/strong\u003e — most commonly due to \u003cstrong data-start=\"941\" data-end=\"966\"\u003eelevated temperatures\u003c\/strong\u003e from hot processes, ovens, or extrusion systems. In these cases, velocity and pressure are measured as normal, but the results \u003cstrong data-start=\"1094\" data-end=\"1116\"\u003erequire correction\u003c\/strong\u003e if they are to be interpreted properly.\u003c\/p\u003e\n\u003cp data-start=\"1158\" data-end=\"1281\"\u003eThe \u003cstrong data-start=\"1162\" data-end=\"1198\"\u003eFluid Mechanics Excel Calculator\u003c\/strong\u003e was created to support those corrections — clearly, transparently, and defensibly.\u003c\/p\u003e\n\u003chr data-start=\"1283\" data-end=\"1286\"\u003e\n\u003ch2 data-start=\"1288\" data-end=\"1338\"\u003eA Practical Tool for Real-World LEV Assessments\u003c\/h2\u003e\n\u003cp data-start=\"1340\" data-end=\"1477\"\u003eThis calculator is designed to help practitioners account for \u003cstrong data-start=\"1402\" data-end=\"1425\"\u003eair density changes\u003c\/strong\u003e where temperature differs from standard conditions.\u003c\/p\u003e\n\u003cp data-start=\"1479\" data-end=\"1491\"\u003eIt supports:\u003c\/p\u003e\n\u003cul data-start=\"1493\" data-end=\"1745\"\u003e\n\u003cli data-start=\"1493\" data-end=\"1543\"\u003e\n\u003cp data-start=\"1495\" data-end=\"1543\"\u003eAdjustment of \u003cstrong data-start=\"1509\" data-end=\"1543\"\u003emeasured (actual) air velocity\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1544\" data-end=\"1604\"\u003e\n\u003cp data-start=\"1546\" data-end=\"1604\"\u003eCalculation of \u003cstrong data-start=\"1561\" data-end=\"1583\"\u003ecorrected velocity\u003c\/strong\u003e based on temperature\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1605\" data-end=\"1664\"\u003e\n\u003cp data-start=\"1607\" data-end=\"1664\"\u003eImproved interpretation of pressure and velocity readings\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1665\" data-end=\"1745\"\u003e\n\u003cp data-start=\"1667\" data-end=\"1745\"\u003eClear differentiation between \u003cem data-start=\"1697\" data-end=\"1707\"\u003emeasured\u003c\/em\u003e and \u003cem data-start=\"1712\" data-end=\"1723\"\u003ecorrected\u003c\/em\u003e results for reporting\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1747\" data-end=\"1943\"\u003eThe approach aligns with guidance from \u003cstrong data-start=\"1786\" data-end=\"1795\"\u003eACGIH\u003c\/strong\u003e and recognised industry practice, acknowledging that while altitude is rarely significant in UK industrial settings, \u003cstrong data-start=\"1913\" data-end=\"1942\"\u003etemperature absolutely is\u003c\/strong\u003e.\u003c\/p\u003e\n\u003chr data-start=\"1945\" data-end=\"1948\"\u003e\n\u003ch2 data-start=\"1950\" data-end=\"1985\"\u003eUnderstanding the Two Velocities\u003c\/h2\u003e\n\u003cp data-start=\"1987\" data-end=\"2090\"\u003eOne of the most common sources of confusion in non-standard air calculations is the difference between:\u003c\/p\u003e\n\u003col data-start=\"2092\" data-end=\"2313\"\u003e\n\u003cli data-start=\"2092\" data-end=\"2204\"\u003e\n\u003cp data-start=\"2095\" data-end=\"2204\"\u003e\u003cstrong data-start=\"2095\" data-end=\"2114\"\u003eActual Velocity\u003c\/strong\u003e\u003cbr data-start=\"2114\" data-end=\"2117\"\u003eThe velocity calculated directly from instrument readings at the time of assessment.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2206\" data-end=\"2313\"\u003e\n\u003cp data-start=\"2209\" data-end=\"2313\"\u003e\u003cstrong data-start=\"2209\" data-end=\"2231\"\u003eCorrected Velocity\u003c\/strong\u003e\u003cbr data-start=\"2231\" data-end=\"2234\"\u003eThe velocity adjusted to account for air density changes due to temperature.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp data-start=\"2315\" data-end=\"2447\"\u003eThe calculator allows both to be determined — and the guidance strongly recommends that \u003cstrong data-start=\"2403\" data-end=\"2446\"\u003eboth values are recorded in LEV reports\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"2449\" data-end=\"2466\"\u003eWhy this matters:\u003c\/p\u003e\n\u003cul data-start=\"2468\" data-end=\"2740\"\u003e\n\u003cli data-start=\"2468\" data-end=\"2552\"\u003e\n\u003cp data-start=\"2470\" data-end=\"2552\"\u003eThe \u003cem data-start=\"2474\" data-end=\"2491\"\u003eactual velocity\u003c\/em\u003e provides a reliable comparison point for future site visits.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2553\" data-end=\"2654\"\u003e\n\u003cp data-start=\"2555\" data-end=\"2654\"\u003eThe \u003cem data-start=\"2559\" data-end=\"2579\"\u003ecorrected velocity\u003c\/em\u003e provides a more accurate engineering interpretation of system performance.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2655\" data-end=\"2740\"\u003e\n\u003cp data-start=\"2657\" data-end=\"2740\"\u003eUsing the wrong velocity in volume calculations can lead to \u003cstrong data-start=\"2717\" data-end=\"2739\"\u003esignificant errors\u003c\/strong\u003e.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"2742\" data-end=\"2745\"\u003e\n\u003ch2 data-start=\"2747\" data-end=\"2788\"\u003eImportant Notes on Volumetric Flowrate\u003c\/h2\u003e\n\u003cp data-start=\"2790\" data-end=\"2833\"\u003eWhen working under non-standard conditions:\u003c\/p\u003e\n\u003cul data-start=\"2835\" data-end=\"3088\"\u003e\n\u003cli data-start=\"2835\" data-end=\"2917\"\u003e\n\u003cp data-start=\"2837\" data-end=\"2917\"\u003eThe standard velocity–volume–area triangle \u003cstrong data-start=\"2880\" data-end=\"2917\"\u003ecannot always be applied directly\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2918\" data-end=\"2995\"\u003e\n\u003cp data-start=\"2920\" data-end=\"2995\"\u003eCalculating volume from corrected velocity requires a \u003cstrong data-start=\"2974\" data-end=\"2995\"\u003edifferent formula\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2996\" data-end=\"3088\"\u003e\n\u003cp data-start=\"2998\" data-end=\"3088\"\u003eUsing the wrong relationship can return a volumetric flowrate that is materially incorrect\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3090\" data-end=\"3199\"\u003eThis tool helps avoid that pitfall — but only when used by someone who understands the underlying principles.\u003c\/p\u003e\n\u003chr data-start=\"3201\" data-end=\"3204\"\u003e\n\u003ch2 data-start=\"3206\" data-end=\"3247\"\u003eProfessional Boundaries and Exclusions\u003c\/h2\u003e\n\u003cp data-start=\"3249\" data-end=\"3303\"\u003eThis calculator is intentionally \u003cstrong data-start=\"3282\" data-end=\"3302\"\u003elimited in scope\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"3305\" data-end=\"3333\"\u003eIt does \u003cstrong data-start=\"3313\" data-end=\"3320\"\u003enot\u003c\/strong\u003e account for:\u003c\/p\u003e\n\u003cul data-start=\"3335\" data-end=\"3417\"\u003e\n\u003cli data-start=\"3335\" data-end=\"3353\"\u003e\n\u003cp data-start=\"3337\" data-end=\"3353\"\u003eMoisture content\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3354\" data-end=\"3372\"\u003e\n\u003cp data-start=\"3356\" data-end=\"3372\"\u003eGases or vapours\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3373\" data-end=\"3417\"\u003e\n\u003cp data-start=\"3375\" data-end=\"3417\"\u003eMixed airstreams with changing composition\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3419\" data-end=\"3640\"\u003eThese factors also affect air density and require \u003cstrong data-start=\"3469\" data-end=\"3496\"\u003eadditional calculations\u003c\/strong\u003e, as set out in ACGIH guidance. Where they are present, calculations must be carried out by a \u003cstrong data-start=\"3590\" data-end=\"3610\"\u003ecompetent person\u003c\/strong\u003e using appropriate references.\u003c\/p\u003e\n\u003chr data-start=\"3642\" data-end=\"3645\"\u003e\n\u003ch2 data-start=\"3647\" data-end=\"3670\"\u003eImportant Disclaimer\u003c\/h2\u003e\n\u003cp data-start=\"3672\" data-end=\"3734\"\u003eThis tool is provided as a \u003cstrong data-start=\"3699\" data-end=\"3733\"\u003ereference and support aid only\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cul data-start=\"3736\" data-end=\"3952\"\u003e\n\u003cli data-start=\"3736\" data-end=\"3785\"\u003e\n\u003cp data-start=\"3738\" data-end=\"3785\"\u003eEvery effort has been made to minimise errors\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3786\" data-end=\"3846\"\u003e\n\u003cp data-start=\"3788\" data-end=\"3846\"\u003eNo guarantee is given that the spreadsheet is error-free\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3847\" data-end=\"3887\"\u003e\n\u003cp data-start=\"3849\" data-end=\"3887\"\u003eNo liability is accepted for its use\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3888\" data-end=\"3952\"\u003e\n\u003cp data-start=\"3890\" data-end=\"3952\"\u003eUsers are responsible for checking all calculations manually\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3954\" data-end=\"4095\"\u003eIf you choose to use this tool, you are expected to understand the maths, sense-check outputs, and apply professional judgement at all times.\u003c\/p\u003e\n\u003cp data-start=\"4097\" data-end=\"4153\"\u003eFeedback on errors or issues is welcomed and encouraged.\u003c\/p\u003e\n\u003chr data-start=\"4155\" data-end=\"4158\"\u003e\n\u003ch2 data-start=\"4160\" data-end=\"4184\"\u003eWhy This Tool Matters\u003c\/h2\u003e\n\u003cp data-start=\"4186\" data-end=\"4240\"\u003eFailing to account for non-standard air can result in:\u003c\/p\u003e\n\u003cul data-start=\"4242\" data-end=\"4411\"\u003e\n\u003cli data-start=\"4242\" data-end=\"4271\"\u003e\n\u003cp data-start=\"4244\" data-end=\"4271\"\u003eMisinterpreted velocities\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4272\" data-end=\"4322\"\u003e\n\u003cp data-start=\"4274\" data-end=\"4322\"\u003eIncorrect performance comparisons year-to-year\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4323\" data-end=\"4361\"\u003e\n\u003cp data-start=\"4325\" data-end=\"4361\"\u003ePoorly justified Reg 9 conclusions\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4362\" data-end=\"4411\"\u003e\n\u003cp data-start=\"4364\" data-end=\"4411\"\u003eConfusion during audits or enforcement visits\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"4413\" data-end=\"4550\"\u003eThis calculator helps practitioners \u003cstrong data-start=\"4449\" data-end=\"4522\"\u003ethink clearly, record transparently, and justify decisions defensibly\u003c\/strong\u003e — without hiding the maths.\u003c\/p\u003e\n\u003chr data-start=\"4552\" data-end=\"4555\"\u003e\n\u003ch2 data-start=\"4557\" data-end=\"4586\"\u003eWho This Calculator Is For\u003c\/h2\u003e\n\u003cp data-start=\"4588\" data-end=\"4614\"\u003eThis tool is intended for:\u003c\/p\u003e\n\u003cul data-start=\"4616\" data-end=\"4782\"\u003e\n\u003cli data-start=\"4616\" data-end=\"4657\"\u003e\n\u003cp data-start=\"4618\" data-end=\"4657\"\u003eLEV engineers and COSHH Reg 9 testers\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4658\" data-end=\"4685\"\u003e\n\u003cp data-start=\"4660\" data-end=\"4685\"\u003eOccupational hygienists\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4686\" data-end=\"4716\"\u003e\n\u003cp data-start=\"4688\" data-end=\"4716\"\u003eAdvanced LEV practitioners\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4717\" data-end=\"4782\"\u003e\n\u003cp data-start=\"4719\" data-end=\"4782\"\u003eThose working with hot processes or elevated air temperatures\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"4784\" data-end=\"4899\"\u003eIt is best used alongside formal guidance such as \u003cstrong data-start=\"4834\" data-end=\"4866\"\u003eACGIH Industrial Ventilation\u003c\/strong\u003e and \u003cstrong data-start=\"4871\" data-end=\"4898\"\u003eLEV107: Basic LEV Maths\u003c\/strong\u003e.\u003c\/p\u003e\n\u003chr data-start=\"4901\" data-end=\"4904\"\u003e\n\u003ch2 data-start=\"4906\" data-end=\"4924\"\u003eProduct Details\u003c\/h2\u003e\n\u003cul data-start=\"4926\" data-end=\"5251\"\u003e\n\u003cli data-start=\"4926\" data-end=\"4996\"\u003e\n\u003cp data-start=\"4928\" data-end=\"4996\"\u003e\u003cstrong data-start=\"4928\" data-end=\"4940\"\u003eProduct:\u003c\/strong\u003e Tools of the Trade – Fluid Mechanics Excel Calculator\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4997\" data-end=\"5040\"\u003e\n\u003cp data-start=\"4999\" data-end=\"5040\"\u003e\u003cstrong data-start=\"4999\" data-end=\"5010\"\u003eFormat:\u003c\/strong\u003e Microsoft Excel spreadsheet\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5041\" data-end=\"5115\"\u003e\n\u003cp data-start=\"5043\" data-end=\"5115\"\u003e\u003cstrong data-start=\"5043\" data-end=\"5053\"\u003eFocus:\u003c\/strong\u003e Correcting LEV calculations for non-standard air conditions\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5116\" data-end=\"5172\"\u003e\n\u003cp data-start=\"5118\" data-end=\"5172\"\u003e\u003cstrong data-start=\"5118\" data-end=\"5131\"\u003eBased On:\u003c\/strong\u003e ACGIH principles and industry practice\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5173\" data-end=\"5207\"\u003e\n\u003cp data-start=\"5175\" data-end=\"5207\"\u003e\u003cstrong data-start=\"5175\" data-end=\"5186\"\u003eAuthor:\u003c\/strong\u003e Louise Davies Wood\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5208\" data-end=\"5251\"\u003e\n\u003cp data-start=\"5210\" data-end=\"5251\"\u003e\u003cstrong data-start=\"5210\" data-end=\"5234\"\u003eOriginally Released:\u003c\/strong\u003e September 2022\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"LEV Academy","offers":[{"title":"Default Title","offer_id":52700439413075,"sku":null,"price":55.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1017\/3313\/8771\/files\/Screenshot2026-01-01212349_483926f9-0cc0-4f6c-b17b-f841038c82c4.png?v=1767302727","url":"https:\/\/www.levacademy.co.uk\/products\/tools-of-the-trade-fluid-mechanics-excel-calculator","provider":"LEV Academy","version":"1.0","type":"link"}