Touch Hold Function (Hold) - Fluke 8808A/SU User Manual

Impedance
8000 Ω
1200 Ω
1000 Ω
[1]
900 Ω
800 Ω
600 Ω
500 Ω
[1] Voltage annunciator lit
[2] Audio power readings possible
To access the reference impedance list, press Q then press W. The reference
impedance currently selected is displayed, along with the "db" and "ohm" annunciators.
Press U or V to scroll to the desired value, then press R to select a reference
impedance and return the primary display to the measurement function. Press any
function or modifier button to exit the reference impedance list without selecting a new
value.
Setting the dB reference resistance to 16, 8, 4, or 2 ohms allows you to use the Meter to
calculate audio power. After the reference resistance has been set to 16, 8, 4, or 2 ohms,
press W twice to select the audio power modifier. Power annunciator will be displayed.
The following equation is used to make a power calculation (volts is the measurement
value):

Touch Hold Function (HOLD)

The Touch Hold function holds the results of your measurements on the display. Touch
Hold is helpful in difficult or hazardous circumstances when you want to keep your eyes
fixed on the probes and reading the display only when it is safe or convenient to do so.
When a new, stable reading is detected, a beep is emitted and the display is automatically
updated.
To select the Touch Hold function, press I. H is displayed. In Touch Hold, each
time you press I, a new reading is displayed. To exit the Touch Hold function, press
and hold I for 2 seconds.
If you are in the autorange mode when Touch Hold is selected, you will autorange to the
correct range. If you are in the manual range mode when Touch Hold is selected, you will
be in the fixed range you were in when Touch Hold was selected.
The Touch Hold function can be combined with the minimum/maximum modifier to hold
and update only when a new minimum or maximum value is detected. To force the
display to update, with Touch Hold selected press I for less than 2 seconds.
The Meter allows you to choose the minimum response level needed for Touch Hold to
capture and display a measurement. You can choose from the following four response
levels:
Table 3-5. dBM Reference Impedances
Impedance
300 Ω
250 Ω
150 Ω
135 Ω
125 Ω
124 Ω
110 Ω
Volts
=
Audio Power
Operating the Meter from the Front Panel
Selecting a Function Modifier
Impedance
2
R
ref
93 Ω
75 Ω
50 Ω
16 Ω
[2]
8 Ω
[2]
4 Ω
[2]
2 Ω
[2]
3
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