2014年8月15日 · What is the Oxygen Tolerance Unit (OTU)? One OTU or one UPTD (Unit Pulmonary Toxic Dose), the names can be used interchangeably, is the equivalent to breathing 100% oxygen for one minute at 1 ATA. As a safety margin we should not exceed a total of 300 units in a 24 hour period.

The NOAA CNS Oxygen Exposure Limits chart is used for avoiding CNS Oxygen Toxicity problems while conducting multiple dives on one day. The first column represents the maximum oxygen partial pressure exposure in atmospheres.

The NOAA Diving Program uses the following diving tables to calculate maximum depths and diving intervals: Air Dives - NOAA No-Decompression Table for Air Dives; Nitrox Dives - NOAA No-Decompression Table for Nitrox Dives; Publications. …

One UPTD (or OTU) is the degree of pulmonary oxygen toxicity produced by breathing 100% O2 continuously at a pressure of 1 atmosphere absolute (ATA) for 1 minute. The CPTD calculation (see Equation 1 below) converts any continuous oxygen exposure (PO above 0.5) and time combination to be expressed as UPTD’s (or OTU’s).

2015年3月23日 · The CNS value (short for Central Nervous System Oxygen Toxicity) is a measure of how long you have been exposed to elevated partial pressures of oxygen (PPO2) as a percentage of a maximum allowable exposure time. As PPO2 goes up, the maximum allowable exposure time goes down. The table we use is from the NOAA Diving Manual (Fourth Edition):

Oxygen exposure tracking is important in technical and rebreather diving. Use these tables to determine the Percent CNS O2 clock or Oxygen Toxicity Units (OTU) for any time exposure to PO2's from 0.60 ATA to 1.60 ATA in 0.05 ATA increments.

The National Oceanic and Atmospheric Administration (NOAA) recommends a more conservative 180 minutes at 1.3 ATA for normal exposures and 240 minutes only for exceptional exposures. The Professional Association of Diving Instructors (PADI) has proposed a limit of 1.4 ATA for open-circuit nitrox scuba diving.

The last column tabulates a pulmonary exposure dose, Υ, for divers, called the oxygen tolerance unit (OTU), developed by Lambertsen and coworkers at the University of Pennsylvania. Formally, the oxygen tolerance, Υ, is given by, and can be cumulatively applied to diving exposures according to the following prescriptions

2012年7月16日 · Turns out according to NOAA you're allowed 1440 OTUs in a day (O2 at 1.0 ATA for a 24 hour period). The recommended maximums in the tables come from leaving enough OTUs to tolerate a USN TT6 recompression session. A TT6 is approximately 600 OTUs; 1440-600 = 840, rounded up to 850 for the first day.

OTU (Oxygen Tolerance Unit) Cet utilitaire permet de calculer l'intoxication O2 à long terme (Effet Lorrain Smith) et d'estimer le risque de "pneumonie chimique". Les calculs sont basés sur les indication du NOAA (National Oceanographic and Atmospheric Administration -USA)