How do we test Totobobo mask?

We have not yet figured out what the causes of the relatively poor results were from the CCA (China Consumer Association) test report last month. What we can do now is to share how we conduct our own test to ensure a high level of protection is achievable with Totobobo mask. Even Though Totobobo mask is not a certified N95 mask, we make use of an OSHA-compliant fit-tester called PortaCount® Pro+, which is manufactured by TSI in USA.

由于资料不足我们还没法弄清楚为什么Totobobo在上月中国消费者协会（CCA）的测试报告中表现较差。但我们可以公开我们是如何测试Totobobo口罩，以确定它对PM2.5的高度防护作用。Totobobo不是一个N95认证的口罩，但我们采用符合OSHA标准，由美国TSI公司制造的定量测试仪，PortaCount® Pro+。

HOW DOES THE FIT-TESTER WORK?
The PortaCount® Respirator Fit Tester works by measuring the concentration of microscopic dust particles in the ambient air and then measuring the concentration of those dust particles that leak into the respirator. The ratio of these two concentrations is called the Fit Factor.

PortaCount® Pro+ 的工作原理为何？它是如何进行口罩测试仪工作？
PortaCount® Pro+ 有两根导管，一根通往口罩测量口罩内的微小颗粒的浓度。另外一根在口罩外测量周围空气的微小颗粒的浓度。PortaCount® Pro+ 根据这两个浓度的比值计算出总保护率（Fit Factor），这包括过滤效率和泄漏性.

WHAT IS A FIT FACTOR?
A fit factor is a measure of how well a particular face piece seals against a person’s face. It is expressed as a ratio of the concentration of challenge aerosol outside a respirator to the concentration of aerosol that leaks into the respirator through the face seal. A fit factor of 100 means the air inside the mask is 100 times cleaner than the air outside.

什么是总保护率-Fit Factor？
总保护率-Fit Factor是指一个口罩对某一个使用者人的总体保护程度。以口罩内外空气中两个颗粒的浓度的比值计算。总保护率-Fit Factor =100 即是表示面罩内的空气比外面的空气清洁器100倍。N95口罩的总保护率-Fit Factor必虽达到100。

WHY IS QUANTITATIVE FIT TESTING (QNFT) BETTER THAN QUALITATIVE FIT TESTING (QLFT)?
The PortaCount® Pro is a Quantitative fit tester (QNFT). QNFT is a better test because it eliminates the subjectivity of QLFT. A quantitative fit test is not affected by the person’s sense of smell, taste or sensitivity to irritant chemicals. One of the most appreciated aspects of QNFT is that the test subject cannot deceive the test operator, as often happens with QLFT.

为什么定量测试比定性测试更准确？
PortaCount® Pro+是一款定量测试仪。 定量测试比定性测试更好，因为它消除了定性测试中会影晌结果的一些主观因素。例如受试者的嗅觉，味觉或对刺激性化学品的敏感度。在定量测试中测试受试者不可能欺骗测试仪。

Below is a 9 minutes video showing the entire process of a Quantitative fit test. The final result shows the Totobobo mask with a pair of F96 filters is able to reduce ambient particles by 142 times (Video @ 8:48), or a fit-factor of 142.

以下是一段9分钟的视频显示PortaCount® Pro+定量测试的全个过程。最终的结果显示Totobobo口罩可以提供142的总保护率（Fit Factor）。面罩内的空气比外面的空气清洁器142倍，即总过滤效率=1-1/142=99.3%。（视频@8:48） http://tinyurl.com/totobobo-test

Fit-test-Totobobo Mask with TSI Portacount Pro 8038 from Francis Chu on Vimeo.

Intro to Quantitative Fit Testing (TSI)

Totobobo mask in NIOSH site for “No Fit Test Respirator”

Clearly a Better Way to Check for Safety