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FONIX FP40 Portable Hearing Aid Analyzer
3.4.3 Viewing multiple measurements
It’s often useful to view several different frequencies responses together on the same screen. This is
especially important when testing AGC hearing aids. To do this, use the Multi-curve function.
To take multiple measurements:
1. Look at the screen just above F2 and F3. If one of them is “OFF MULTICRV,” press the corre-
sponding function button (F2 or F3) to turn it on. Skip to step 6. Otherwise, proceed to step
2 for instructions on selecting Multi-curve for F2 or F3.
2. Press F1 to enter the General Setup Menu.
3. Use the AMPLITUDE and FREQUENCY knobs to select MAIN F2 or MAIN F3. Press START/
STOP repeatedly to select MULTICRV.
4. Press F1 to return to the Main Coupler Screen.
5. Press the function key (F2 or F3) that says “OFF MULTICRV” to turn it on.
6. Look at the screen. In the upper right hand corner of the screen, you will see a MULTICURVE
REPORT box that will contain a legend for four curves. This will give you data about each
curve.
7. Press F6 to select the curve you want to use for the measurement.
8. Follow the directions found in Section 3.4.2 for instructions on how to take a frequency
response measurement.
9. Repeat steps 6-8 to take up to four distinct measurements. If you select a curve that already
contains a frequency response, the old frequency response will be erased when you take a
new response.
To turn off the display of a curve:
1. Press F6 to select the desired curve.
2. Press F7 to turn off the display of that curve. This will not erase the curve.
3. Press F7 to redisplay the curve.
To erase a curve:
There are two ways to erase a curve.
• Press F8. This will erase all four curves in the Multi-curve buffer.
• Press F6 to select the desired curve, and take a new measurement. This will replace the old
curve with the new curve.
3.4.4 Taking a single frequency response
1. Look at the first line in the STATUS box in the Main Coupler Screen. If it says PURE-TONE or
BURST, skip to step 6. Otherwise, proceed to step 2.
