来自 昏昏睡睡HSE · From Drowsy HSE CSP DAILY LEARNING · DAY 28

公式表与备考系统 · 要点进阶 | Formula Sheet & Study System · Key Points in Depth

第 5 块 · 备考基线 · Exam Baseline第 2 / 5 课 · 要点进阶Lesson 2 of 5 · Key Points in Depth

本课只做一件事：把「公式表与备考系统」的四条要点逐条拆开：机制是什么、什么时候成立、最容易错在哪。

Take the four key points of Formula Sheet & Study System apart: mechanism, conditions, and the usual misread.

本课不涉及：不重复概念定义，也不做综合题——只把要点讲透。
Not covered here: No repeat of definitions, no mixed questions — just the points, in depth.

先看一张图 | One picture first

先判断题目在问「频率 / 严重度 / 剂量」，再代入——顺序反了就会用错公式 频率 Rate 病例数 ÷ 工时 × 200,000 TRIR / DART / LTIR 差别只在分子 严重度 Severity 损失工作日 ÷ 工时 × 200,000 回答「伤得多重」 与频率不同轴 剂量 Dose TWA = Σ(Ci×Ti) ÷ 8 D = 100 × Σ(Ci÷Ti) 噪声 Ti：90→8h 95→4h 100→2h 105→1h 先统一量纲：ppm ↔ mg/m³ 需分子量（mg/m³ = ppm × MW ÷ 24.45）；「人数」不是「工时」。 算完先看量级：TRIR 通常 0.5–10，出现 20 以上几乎一定是分母用了 200,000 而不是实际工时。
图解 / Figure：示意图（本站绘制，非官方图）/ Site-drawn diagram for study, not an official graphic.

本课目标 | Learning objectives

  1. 按顺序复述四条要点各自的机制
  2. 对每条要点说出一个常见误解，并说明为什么错
  3. 判断一个新例子属于哪一条要点

  • Recite the mechanism behind each of the four points
  • Name one common misread per point and why it fails
  • Classify a new example under the right point

    • 图片预览 / Photo preview

    图片经过压缩后保存在当前浏览器。导出失败时，可在下方预览图片上长按保存。/ The photo is compressed and stored in this browser. If download fails, long-press the preview below to save it.

    要点逐条拆 | Point by point

    1. 所有「率」的分母是暴露工时，不是人数
    Every rate is per exposure hours, not per head
    行业统一基准是 200,000 小时 = 100 名全职工人 × 40 小时 × 50 周。用统一基准，不同规模的工厂才能比较。人数会随加班、兼职、外包、季节性用工严重失真，工时才是真实暴露量。
    The common base is 200,000 hours = 100 full-time workers × 40 hours × 50 weeks, which makes plants of different sizes comparable. Headcount distorts badly with overtime, part-time, contractors and seasonality; hours are the real exposure.
    常见误解 / Common misread：拿「我们有 300 人」当分母，或者算完忘了把实际工时换算到 200,000 基准。
    Using 'we have 300 people' as the denominator, or forgetting to scale actual hours to the 200,000 base.
    2. TRIR / DART / LTIR 的差别只在分子
    TRIR, DART and LTIR differ only in the numerator
    可记录病例包括：超出急救范围的医疗处置、意识丧失、转岗或工作受限、缺勤。急救（first aid）不计。TRIR 分子是全部可记录病例；DART 是缺勤 + 工作受限 + 转岗；LTIR 只算缺勤。三个率共用同一个分母。
    Recordable cases include medical treatment beyond first aid, loss of consciousness, restricted work or transfer, and days away. First aid does not count. TRIR counts all recordables; DART counts days away plus restricted or transferred; LTIR counts days away only. All three share one denominator.
    常见误解 / Common misread：把急救算进 TRIR（数字虚高、看着更安全），或把 DART 当「所有伤害」（数字偏低）。
    Counting first aid in TRIR (inflates the rate and flatters the plant) or reading DART as all injuries (understates it).
    3. 平均浓度不等于时间加权平均
    An average concentration is not a TWA
    TWA = Σ(浓度 × 时长) ÷ 8，用 8 小时班归一。短时高峰要先摊到 8 小时再和 PEL 比；有 ceiling 限值的物质例外，峰值必须单独看。噪声剂量 D = 100 × Σ(Ci ÷ Ti)，Ti 是该声级的允许时长（90 dBA→8 h，95→4 h，100→2 h，105→1 h，115→0.25 h），D = 100 对应 85 dBA 的 8 小时标准。
    TWA = Σ(concentration × time) ÷ 8, normalised to an 8-hour shift. Short peaks must be spread over 8 hours before comparison with a PEL, except for substances with a ceiling. Noise dose D = 100 × Σ(Ci ÷ Ti) where Ti is the allowed duration at that level (90 dBA→8 h, 95→4 h, 100→2 h, 105→1 h, 115→0.25 h); D = 100 corresponds to 85 dBA for 8 hours.
    常见误解 / Common misread：拿 15 分钟测得的峰值直接和 8 小时 PEL 比，然后判超标；或把 90 dBA 的 8 小时允许值误用到 100 dBA。
    Comparing a 15-minute peak directly with an 8-hour PEL and calling it an overexposure, or applying the 8-hour allowance for 90 dBA to 100 dBA.
    4. 先统一量纲与单位，再代入
    Fix units and magnitudes before substituting
    ppm 与 mg/m³ 换算需要分子量：mg/m³ = ppm × MW ÷ 24.45（25 ℃）。「每 100 名工人」与「每 200,000 小时」不是同一个分母。题干里英尺与米、美元与千美元、班次与小时经常混着给。算完先看量级：TRIR 通常在 0.5–10，出现 20 以上几乎一定是分母没换算。
    ppm to mg/m³ needs molecular weight: mg/m³ = ppm × MW ÷ 24.45 at 25 °C. 'Per 100 workers' and 'per 200,000 hours' are different denominators. Items freely mix feet and metres, dollars and thousands, shifts and hours. Check magnitude after computing: TRIR normally sits between 0.5 and 10; above 20 almost always means the denominator was not scaled.
    常见误解 / Common misread：算出 TRIR = 20.8 还照抄进答案，不做量级检查——这一步只要两秒。
    Copying TRIR = 20.8 into the answer without a magnitude check — a two-second step.

    情景自测 | Scenario check

    考点应用Exam-point application

    这道题考什么：考分母与分子的选择：同一组数据算两个率，看是否分清。
    Tests denominator and numerator choice: two rates from one data set.

    一家 500 人工厂全年 1,000,000 工时，9 起可记录病例，其中 3 起缺勤、2 起转岗，其余 4 起为医疗处置但未缺勤。TRIR 与 DART 分别是？

    A 500-person plant logs 1,000,000 hours, 9 recordable cases: 3 with days away, 2 with job transfer, 4 with medical treatment but no lost time. What are TRIR and DART?

    自编练习题，不是 BCSP 官方真题，也不能用来预测分数。 / Original practice item, not an official BCSP exam question.

    动手练 | Practice

    1. 用你所在单位去年的工时与病例，算出 TRIR 与 DART，并做一次量级检查。
    Compute TRIR and DART for your site using last year's hours and cases, then run a magnitude check.

    学习打卡与笔记 | Progress & notes

    已完成 0/4 项 / 0/4 tasks complete

    连续学习 / Learning streak: 0 天 / 0 days

    进度保存在当前浏览器，不会自动跨设备同步。/ Progress is stored in this browser only.

    PNG 学习记录预览；可长按图片保存 / PNG card preview; long-press to save

    可靠来源 | Official references

    BCSP — CSP Examination Blueprint (CSP11)

    BCSP — Official Self-Assessments

    BCSP — Certified Safety Professional (CSP)

    Pearson VUE — CSP 考试预约 / Scheduling

    本课为一般性学习资料，不替代现场专业评估、法规要求或组织程序。/ Educational content only.

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