暴露限值是多少？怎么变的？
What are the exposure limits, and how have they changed?
加上 PTFE 衰减片和 80° 视场盖，低成本胶片徽章可做数周的人员远紫外剂量监测，并能估算眼部剂量。
With a PTFE attenuator and an 80° field-of-view cap, low-cost film badges can monitor occupant far-UVC dose for weeks and estimate eye dose.
研究方法
Method
在 OC-1 辐射显色胶片（最低可测 5 mJ/cm²，精度 ±10%）上加两样配件：① 1.6mm 厚 PTFE（特氟龙）片，只透过约 6.9% 的 222nm 和 12% 的 254nm；② 开单孔的亚克力盖，把视场限制在 80°，模拟眉骨和眼眶对眼睛的遮挡。两者都在 222nm 光源下校准。之后，加拿大新斯科舍省 3 家长期护理机构在一项 222nm 灯与外观相同的安慰剂灯的随机试验中，让员工把带 PTFE 的胶片徽章佩戴在肩部，约两周内累计 47–257 小时。
OC-1 radiochromic film (measures from 5 mJ/cm², ±10%) was fitted with (1) a 1.6 mm PTFE sheet transmitting about 6.9% of 222 nm and 12% of 254 nm, and (2) an acrylic cap with one aperture that limits the field of view to 80°, mimicking shielding by the brow and eye socket. Both were calibrated against a 222 nm source. PTFE-covered badges were then worn on the shoulder by staff at three long-term care homes in Nova Scotia, Canada, during a randomized trial of 222 nm versus identical placebo lamps, for 47–257 hours over about two weeks.
能证明什么What it shows
PTFE 让 222nm 的可测量程扩大约 14 倍，并挡住胶片变色，佩戴者无从得知自己所在区域装的是真灯还是安慰剂灯。80° 视场盖的 50% 响应截止角在约 ±40°（不加 PTFE 用 10.7mm 孔，加 PTFE 用 9.6mm 孔），与理论余弦响应吻合；由于 PTFE 会散射光、使视场变大，孔径必须实测校准，不能只靠计算。养老院实测累积剂量 28–362 mJ/cm²，折合每 8 小时约 4–13 mJ/cm²。作为参照，2022 年 ACGIH 对 222nm 的每日限值为眼睛 160 mJ/cm²、皮肤 479 mJ/cm²。不少读数超过 200 mJ/cm²，不加 PTFE 的胶片在这个剂量下早已饱和。
PTFE extends the usable range about 14-fold at 222 nm and hides the film's colour change, so wearers stay blind to whether their area has active lamps. The 80° cap gave a 50% response cut-off near ±40° (10.7 mm aperture without PTFE, 9.6 mm with), matching a cosine response; because PTFE scatters light and widens the field, apertures must be calibrated rather than calculated. In the care homes, accumulated doses were 28–362 mJ/cm², about 4–13 mJ/cm² per 8 hours. For reference, the 2022 ACGIH daily limits at 222 nm are 160 mJ/cm² for eyes and 479 mJ/cm² for skin. Many readings exceeded 200 mJ/cm², which would have saturated bare film.
不能证明什么What it does not show
肩部徽章测的是肩部剂量，不是眼睛剂量；80° 视场盖只在实验台上做了表征，养老院案例中并未佩戴。方法依赖严格管理：要记录佩戴时长，不用时放进避光盒。这些剂量只描述这一批安装现场，不能套用到其他房间、灯具或灯管数量。本文只报告照射剂量，不涉及该试验的健康结局。
Shoulder badges measure dose at the shoulder, not at the eye; the 80° cap was characterised on the bench, not worn in the care-home case. The method depends on disciplined handling: logging wear time and keeping badges in light-proof cases when not worn. The doses describe one set of installations and do not transfer to other rooms, fixtures or lamp counts. The paper reports exposure only, not the trial's health outcomes.
备注Note
为安装方和验收方提供一种低成本手段，证明调试后人员（含眼部）照射低于限值。可与 S4-01（2022 年 ACGIH 限值修订）、S4-02（吸顶灯具下的眼部与面部剂量）对照阅读。
A cheap way for installers and auditors to show occupant and eye exposure stays under limits after commissioning. Read with S4-01 (the 2022 ACGIH limit revision) and S4-02 (ocular and facial doses from ceiling fixtures).