Witschi Electronic Ltd
Analyzer Q1
Page 27
The electrical stray field of the LCD display is used for the rate measurement of LCD watches. The
stray field is recorded capacitively. The instrument can only process binary frequencies (watches
with 32.768 kHz quartz frequency).
Caution
The LCD operating frequency cannot be measured through the supply current. The
LCD
signal source cannot therefore be used when the Analyzer Q1 supplies the LCD
watch.
The instrument recognizes the signals from LCD displays and selects itself the correct signal source.
The watch must be positioned on the signal transducer with the dial face downward.
The
LCD display
LED indicates the strength of the recorded signal. If the signal is too weak, it is
necessary to shift or rotate slightly the watch on the transducer to find a better location for
capturing the signal.
Measuring the rate with the LCD frequency of certain LCD watches is difficult or impossible, since
the information for the rate measurement is not available in the operating frequency of the display.
Such watches can often be measured through the quartz frequency (see chapter 6).
Measurement Time
LCD watches without inhibition compensation can be measured with the shortest measurement time
of 2 s. The measurement of watches with inhibition compensation must be performed during an
inhibition period or a multiple thereof.
When the
Time
parameter is set to
Auto
, the correct measurement time is selected automatically.
The desired time can also be selected manually for special measurements.
16.1.5
Quartz Signal Source
Watches with a 32 kHz quartz frequency and rate compensation of the oscillator (with chip capacitor
or trimmer) can be tested in this mode. Due to its short measurement time, this test method is
ideally suited for watches with oscillator compensation.
Caution
Due to the risk of faulty measurements in the case of inhibition-compensated watches,
this signal source is not selected automatically. It is necessary to select manually the
Quartz
signal source with the
Signal
parameter to perform a rate measurement
through the quartz frequency.
Signal Acquisition
The mechanical quartz oscillations of watches in a metal case are acoustically recorded. The
electrical stray field from the quartz oscillator is capacitively recorded with watches enclosed in a
case of synthetic material or with open movements. The quartz frequency is derived from the supply
current if the Analyzer Q1 is supplying the watch. The switching to the suitable signal recording
occurs automatically.
The watch must be positioned on the signal transducer with the back downward.
For acoustic signal recording (watches with metal case), the watch must be in contact with the
transducer stick.
The
quartz 32kHz
LED indicates the strength of the recorded signal. If the signal is too weak, it is
necessary to shift slightly the watch on the transducer to find a better location for capturing the
signal.
Measurement Time
In automatic mode, the shortest measurement time of 2 s is selected. It is possible to select a longer
time manually.
