Further Functions - TTI 1604 Manual De Instrucciones

The further functions of Null, Hold, T-Hold and Min-Max are all selected by pressing SHIFT
followed by the appropriate key; the shifted function is shown in blue above the key.
Null
Selecting Null stores the current reading and subtracts it from all the following readings. The
meter range is locked and Null shows in the display. Hold, T-Hold and Min-Max can all be
subsequently selected but changing function or range (or selecting Auto) will automatically cancel
Null. Null can also be cancelled by pressing SHIFT followed by Null.
Null can be used to null out the effect of residual test lead resistance on the lower Ohms ranges.
Select the appropriate Ohms range using the arrowed up/down keys. Connect the test leads
together, wait for the reading to settle and select Null. Make the Ohms measurements in the usual
way but note that if Auto is reselected or if the range is changed then Null will be cancelled. Null
cannot be used with Hz.
Hold
Selecting Hold freezes the reading in the display and flashes the Hold annunciator. Hold can be
used with the Null already selected but Null and Min-Max cannot be selected once Hold is set.
Selecting any other function (including range change, Auto/Man and T-Hold) will set that function
and cancel Hold. Hold cannot be used with Hz.
T-Hold
In T-Hold (Touch and Hold) mode the meter will hold a reading until a new non-zero
measurement has been detected; this allows the user to touch-probe the measurement point,
remove the probes and read the meter afterwards. Care should be taken, however, when using T-
Hold with the most sensitive voltage ranges; when the probes are lifted from the circuit being
measured their high impedance means that stray pick-up might generate another 'valid' reading
and the true T-Hold reading may be lost. Selecting T-Hold locks the meter range and shows the
T-Hold annunciator in the display. When T-Hold is initially selected it is automatically 'armed' and
the first valid (non-zero) reading will cause the display to update with a beep and the T-Hold
annunciator to flash.
The meter will re-arm (2 beeps) when it subsequently sees a near-zero reading (because, for
example, the probes have been removed from the measurement) but the original reading is held
in the display. After the 2 beeps the T-Hold annunciator stops flashing to confirm that the meter is
armed and a new reading is taken when the probes next make a non-zero measurement. With
Ohms and continuity measurements, overflow, associated with the probes being open-circuit, re-
arms the meter. For all functions a measurement change of more than 1000 counts will also
initiate a re-arm/new measurement cycle. T-Hold can be used with Null already selected but Null
and Min-Max cannot be selected once T-Hold is set. Selecting any other function (including range
change, Auto and Hold) will set that function and cancel T-Hold.
T-Hold cannot be used with Hz.
Min-Max
While Min-Max is selected the minimum (most negative) and maximum (most positive) readings
are stored. The Min and Max readings can be displayed, while Min-Max is running, by using the
Review function (SHIFT followed by Review). The first SHIFT/Review displays the Minimum,
indicated by flashing the Min annunciator; the second SHIFT/Review displays the Maximum (Max
flashes); the third SHIFT/Review returns the display to normal with Min-Max still running.
Min-Max can be turned off by pressing SHIFT/Min-Max again. Selecting another function or range
or Auto also cancels Min-Max. Null, Hold and T-Hold cannot be selected with Min-Max running.
Min-max cannot be used with Hz. Review cannot be used with Min-Max turned off.
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Further Functions