Which H2S reading is within the allowable limit of being less than 5 ppm?

Which H2S reading is within the allowable limit of being less than 5 ppm?

• A. 6 ppm
• B. 5 ppm
• C. 4 ppm
• D. 3 ppm

Answer: (C)

When a limit is stated as less than 5 ppm, readings must be under 5 to be acceptable. Among these options, 4 ppm is the closest value to 5 while still staying under it, so it best matches the requirement. A reading of 6 ppm is too high, exceeding the limit. A reading of 5 ppm hits the limit but is not strictly under it, so it doesn’t meet the “less than 5” condition. A reading of 3 ppm is under the limit but farther from 5 than 4, making 4 ppm the best choice as the under-5 reading that’s closest to the threshold.

When a limit is stated as less than 5 ppm, readings must be under 5 to be acceptable. Among these options, 4 ppm is the closest value to 5 while still staying under it, so it best matches the requirement. A reading of 6 ppm is too high, exceeding the limit. A reading of 5 ppm hits the limit but is not strictly under it, so it doesn’t meet the “less than 5” condition. A reading of 3 ppm is under the limit but farther from 5 than 4, making 4 ppm the best choice as the under-5 reading that’s closest to the threshold.