Fluke 189 — понимание режима AutoHOLD и MIN MAX для измерительных приборов [33/96]

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Getting Acquainted

Using AutoHOLD

2-19

Using AutoHOLD

WWarning

AutoHOLD mode does not capture unstable

or noisy readings. Do not use AutoHOLD

mode to determine that circuits are without

power.

To enter AutoHOLD, press OQ(AutoHOLD).

AutoHOLD mode freezes the present reading and its time

stamp. New readings now appear in the secondary

display. See Figure 2-6. When the meter detects a new,

stable reading (>4% change from last stable reading), it

beeps and displays the new reading in the primary

display. You can also force a primary display update by

pressing Q.

If you remove the test leads (open the input), the meter

retains the last frozen primary display.

You cannot use AutoHOLD when MIN MAX is active. With

Model 189, you cannot initiate AutoHOLD while logging

data, but you can initiate logging when AutoHOLD is

active.

To exit AutoHOLD mode, press O Q (AutoHOLD)

again.

Using MIN MAX

The MIN MAX mode stores minimum (MIN) and maximum

(MAX) input values. When the input goes below the stored

minimum value or above the stored maximum value, the

meter beeps and stores the new value. MIN MAX mode

also calculates an average (AVG) of all readings taken

since the mode was activated.

Press M to enter the MIN MAX mode. The maximum

(MAX) reading is displayed first.

Each subsequent press of M steps through the

minimum (MIN), average (AVG), and back to the

maximum reading.

In the MIN MAX mode, the secondary display continues to

show the present measurement value.

The time elapsed since the MIN MAX mode was entered

is shown in the bottom right corner of each type of display.

See Figure 2-7.