Calibration itself is always implemented at a single point in time.  If it is a multipoint calibration, then a slope and intercept are determined.  If it is a single point, then the intercept is held constant and only the slope is recalculated.  Between every point in time where there is a calibration in use the slope and intercept are interpolated as a function of time. 

In Review interpolation affects data forwards and backwards in time. During Acquisition it only affects future Data.

Below are 4 examples:

Multipoint to Single Point

• Multipoint establishes a slope and intercept. (y = m1*nA + b1)
• Single point establishes a new slope for a constant intercept. (y = m2*nA + b1)
• Between these two points m1 is interpolated to m2 as a function of time.  (Same for b1 but since it is constant no change occurs)

Single Point to Single Point

• First single point has a slope and intercept calculated based upon rules such that y = m2*nA + b1
• Second single point has a slope and intercept calculated based upon rules such that y= m3*nA + b1
• Between these two points m2 is interpolated to m3 as a function of time.  (Same for b1 but since it is constant no change occurs)

Single Point to Multipoint

• If no slope and intercept have been previously established then this is the classic example of interpolating backwards. 
  • Multipoint establishes a slope and intercept. (y = m1*nA + b1)
  • PRIOR Single point establishes a new slope for a constant intercept. (y = m0*nA + b1)
  • Between these two points m1 is interpolated to m0 as a function of time.  (Same for b1 but since it is constant no change occurs)
• If a slope and intercept have been established previously… then
  • Single point establishes a new slope for a constant intercept (y = m6*nA + b1) based upon prior calibrations in use
  • Multipoint establishes a slope and intercept. (y = m7*nA + b7)
  • Between these two points m6 and b1 are interpolated to m7 and b7 as a function of time. 

Multipoint to Multipoint

• First Multipoint establishes a slope and intercept. (y = m1*nA + b1)
• Second Multipoint establishes a slope and intercept. (y = m2*nA + b2)
• m1 and b1 are interpolated to m2 and b2 as a function of time.

Examples of interpolation

1. Multipoint to Single - only the slope

2. Single to Single - only the slope

3. Single to Multipoint - slope and intercept

4. Multipoint to Multipoint - slope and intercept