- #1

- 5

- 0

- Homework Statement
- Hello!

I have a straightforward (I think...) uncertainties problem, that I still can't do. I need to calculate the uncertainty (in seconds) in the deadtime of a Geiger tube.

- Relevant Equations
- The formula for deadtime is (approximately) T = (A+B-C)/(2*A*B). A, B and C are all count rates (in counts per second).

A = 209

B = 273

C = 456

I believe that the absolute uncertainty in A is sqrt(A) (I also have a small absolute uncertainty from using a stopwatch).

Does the absolute uncertainty in A+B-C equal √A+√B+√C? If so, this is larger than the value of A+B-C. Surely that can't be right?

For this investigation, I have been working from a lab script from my local uni physics department. This suggested that calculating this actually required a method using partial derivatives. Is this right? (if so, the calculation would probably be beyond the scope of my course, though if I could work it out, I would obviously use it)

I am really struggling with this, and would be massively grateful for any help.

Many thanks!

For this investigation, I have been working from a lab script from my local uni physics department. This suggested that calculating this actually required a method using partial derivatives. Is this right? (if so, the calculation would probably be beyond the scope of my course, though if I could work it out, I would obviously use it)

I am really struggling with this, and would be massively grateful for any help.

Many thanks!