An aggregate correction factor for the 75 µm ( # 200 ) sieve is required when the average difference between the percent passing the 'blank' sample 75 µm ( # 200 ) sieve and the correction factor specimens 75 µm ( # 200 ) sieve is greater than 0.50 percent.

An aggregate correction factor for the 75 µm ( # 200 ) sieve is required when the average difference between the percent passing the 'blank' sample 75 µm ( # 200 ) sieve and the correction factor specimens 75 µm ( # 200 ) sieve is greater than 0.50 percent.

• A. False
• B. True
• C. Only for 150 µm sieve
• D. It is never required

Answer: (B)

In sieve analysis, a correction factor is used when there’s a consistent bias on a specific sieve that affects the measured gradation. For the 75 µm (No. 200) sieve, you compare the percent passing from a blank test with the percent passing from correction-factor specimens on that same sieve. If the average difference between these two measurements is greater than 0.50 percent, you must apply an aggregate correction factor to that sieve to compensate for the bias and obtain an accurate gradation. The 0.50 percent threshold is the criterion that determines when the bias is significant enough to warrant correction; smaller differences are considered within typical testing variability, so no correction is applied. The rule targets the 75 µm sieve specifically, not other sieves, and it isn’t something that’s never required or limited to a different sieve.

In sieve analysis, a correction factor is used when there’s a consistent bias on a specific sieve that affects the measured gradation. For the 75 µm (No. 200) sieve, you compare the percent passing from a blank test with the percent passing from correction-factor specimens on that same sieve. If the average difference between these two measurements is greater than 0.50 percent, you must apply an aggregate correction factor to that sieve to compensate for the bias and obtain an accurate gradation. The 0.50 percent threshold is the criterion that determines when the bias is significant enough to warrant correction; smaller differences are considered within typical testing variability, so no correction is applied. The rule targets the 75 µm sieve specifically, not other sieves, and it isn’t something that’s never required or limited to a different sieve.