How often should the PORTACOUNT be re-calibrated or cleaned?

If the only aerosol you use it with is ambient air, your PORTACOUNT will not need cleaning more than once a year. The unit should zero using the supplied HEPA filter and pass the maximum fit factor test. TSI recommends annual cleaning and re-calibration.

TSI will clean, re-calibrate and, if necessary, replace worn parts for a flat fee. More.

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