To perform a substrate correction you must?

To perform a substrate correction you must?

• A. Add all 6 readings, divide by 6, subtract 1.0 from total
• B. Add all 6 readings, divide by 5, subtract 0.5 from total
• C. Subtract 1.0 from total after averaging 6 readings
• D. Multiply the readings by 6

Answer: (A)

Substrate correction adjusts for bias the surface can introduce into the measurement by using multiple readings and applying a fixed adjustment. You first collect six readings to get a stable sample across the area, then average them by dividing the sum by six. After that, you apply the correction by subtracting 1.0 from that average. This specific sequence—six readings, compute the average, then subtract the 1.0 correction—produces a value that more accurately reflects the true lead level without substrate bias. Using a different number of readings, or a different operation (like multiplying), would not align with this standard correction method, and would leave substrate bias present or distort the result.

Substrate correction adjusts for bias the surface can introduce into the measurement by using multiple readings and applying a fixed adjustment. You first collect six readings to get a stable sample across the area, then average them by dividing the sum by six. After that, you apply the correction by subtracting 1.0 from that average. This specific sequence—six readings, compute the average, then subtract the 1.0 correction—produces a value that more accurately reflects the true lead level without substrate bias. Using a different number of readings, or a different operation (like multiplying), would not align with this standard correction method, and would leave substrate bias present or distort the result.