INTRODUCTION
The purpose of the VOC sensor, is to detect OSHA limits of Formaldehyde, track time and
exposure and provide output so warnings can be given to the operator of the Grossing Station.
BACKGROUND ON OSHA AND FORMALDEHYDE/FORMALIN
1. https://www.osha.gov/OshDoc/data_General_Facts/formaldehyde-factsheet.pdf
2. Formaldehyde is a colorless, strong-smelling gas often found in aqueous (water based)
solutions. Commonly used as a preservative in medical laboratories and mortuaries,
formaldehyde is also found in many products such as chemicals, particle board,
household products, glues, permanent press fabrics, paper product coatings, fiberboard,
and plywood. It is also widely used as an industrial fungicide, germicide and disinfectant.
Although the term “formaldehyde” describes various mixtures of formaldehyde, water,
and alcohol, the term “formalin” is used to describe a saturated solution of formaldehyde
dissolved in water, typically with another agent, most commonly methanol, added to
stabilize the solution. Formalin is typically 37% formaldehyde by weight (40% by volume)
and 6- 13% methanol by volume in water. The formaldehyde component provides the
disinfectant effects of formalin.
SENSOR TYPE
1. The system utilizes two sensing elements that are comprised of a metal oxide
semiconductor layer formed on the alumina substrate of a sensing chip together with an
integrated heater. In the presence of detectable gas, sensor conductivity increases
depending on gas concentration in the air.
PERFORMANCE
1. The sensor will detect levels of Formaldehyde equivalent to
a. Range: 0.2 – 5.0 ppm +/- 15% in a (-)10’C to 50’C environment.
b. Two-point factory calibration at 0.0 and 2.0 ppm formaldehyde
2. The sensor has a warm up time to equalize the sensing environment
a. Warm up: 30 minutes
3. The sensor life is variable depending on exposure levels
a. Life: 1 year when exposure limits do not exceed 3.0 ppm
b. Life detection: 100-hour warning
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