- #1
rocketman46
- 1
- 0
Hi all,
I am just just trying to work out an offset conversion for a sensor I am using, but my transposition is not working out. OK below I will explain:
* Sensor 4 - 20mA coverts to 0 - 20mm/s rms
So:
y = m . x + c
4(mA) = m . 0(mm/s rms) + c therefore tidying up 4(mA) = 0(mm/s rms).m + c
20(mA) = m . 20(mm/s rms) + c therefore tidying up 20(mA) = 20(mm/s rms).m + c
So drawing graph out on paper I make x = 1
Therefore, 20(mA) = 1 . 20(mm/s rms) + c
Transposing 20mA - 20 = c
c = -19.98mA/C
y (mA) = x(mm/ r rms) + c
y (mA) - c = x(mm/ r rms)
so working formula back:
7ma reading on sensor
y (mA) - c = x(mm/ r rms)
7mA -(-19.98mA/C) = 26.98mm/ s rms, which is wrong?
Can somebody help with what I am doing wrong.
Thanks in advance.
I am just just trying to work out an offset conversion for a sensor I am using, but my transposition is not working out. OK below I will explain:
* Sensor 4 - 20mA coverts to 0 - 20mm/s rms
So:
y = m . x + c
4(mA) = m . 0(mm/s rms) + c therefore tidying up 4(mA) = 0(mm/s rms).m + c
20(mA) = m . 20(mm/s rms) + c therefore tidying up 20(mA) = 20(mm/s rms).m + c
So drawing graph out on paper I make x = 1
Therefore, 20(mA) = 1 . 20(mm/s rms) + c
Transposing 20mA - 20 = c
c = -19.98mA/C
y (mA) = x(mm/ r rms) + c
y (mA) - c = x(mm/ r rms)
so working formula back:
7ma reading on sensor
y (mA) - c = x(mm/ r rms)
7mA -(-19.98mA/C) = 26.98mm/ s rms, which is wrong?
Can somebody help with what I am doing wrong.
Thanks in advance.