Racal Dana - 1992 - Counter
Manufacturer:
Equipment:
1992
Date:
1987
Category:
Group:
Sub Group:
Information
GENERAL DESCRIPTION
1.6 The 1991/1992 is a universal timer/counter designed for
system or bench use. Basic measurement functions (described
briefly in Subsection 1.6.2) include Frequency, Period, Time
Interval, Totalize, Phase, and Ratio.
1.6.2 Measurement Functions
1.6.2 Frequency A Function
1.6.2.1.1 Frequency A function is used to measure the
frequency of the signal applied to the Channel A input. A
resolution of nine digits is available with a one-second
gate time.
1.6.2.2 Frequency B Function
1.6.2.2.1 Special Function 21 (see Subsection 3.8 "Special
Functions”), permits Frequency B measurements. Frequency B
function is used to measure the frequency of the signal
applied to the Channel B input. A resolution of nine digits
is available with a one-second gate time.
1.6.2.3 Frequency C Function (Model
1992 only)
1.6.2.3.1 Frequency C function is used to measure the
frequency of the signal applied to the Channel C input. A
resolution of nine digits is available with a one-second
gate time.
1.6.2.4 Period A Function (See Note below)
1.6„2.4.1 Period A function is used to measure the period of
the waveform applied to the Channel A input. A number of
periods, depending upon the resolution (and, therefore, the
gate time) selected, are measured and the average value is
displayed.
Time Interval A-*B Function (See Note below)
1.6.2.5.1 Time Interval function is used to perform
single-shot measurements of the time interval between:
a. An event occurring at the Channel A input and a later
event at the Channel B input (using separate input channels)
b. Two events occurring at the Channel A input (using a
common input channel)
1.6.2.5.2 The arming of the stop circuit can be delayed for
a specific time set by the operator. This feature prevents
the measurement interval being stopped prematurely by
spurious pulses, such as those caused by relay contact bounce.
1.6.2.6 Total A Function (See Note below)
1.6.2.6.1 Total A function permits events occurring at the
Channel A input to be totalized. The counting interval can
be controlled by:
a. Electrical start and stop signals applied to the Channel
B input (Total A by B)
b. Successive operations of a front-panel key (Manual Totalize)
1.6.2.6.2 Delayed arming of the stop circuit to prevent
spurious triggering is available in the Total A by B
measurement mode. The Manual Totalize mode provides the
capability for totalizing cumulatively over a number of periods.
1.6.2 „Phase A rel B Function (See Note below)
1.6.2.7.1 Phase A rel B function is used to measure the
phase difference between the waveform applied to the Channel
A input and that applied to the Channel B input. The phase
difference is displayed in degrees, and indicates the phase
lead at the Channel A input. The signals for phase
measurement must be continuous and have the same frequency.
1.6.2.8 Ratio A/B Function
1.6.2.8.1 Ratio A/B function is used to measure the ratio of
the frequency applied to the Channel A input to that applied
to the Channel B input.
1.6.2.9 Ratio C/B Function (Model
1992 only)
1.6.2.9.1 Ratio C/B function is used to measure the ratio of
the frequency applied to the Channel C input to that applied
to the Channel B input.
NOTE:
Special Function 21 (see Subsection 3.8 "Special Functions")
permits Period B, Time Interval B -**A, Total B by A, and
Phase B rel A. For these functions, note the following:
a. Period B is specified down to 10 ns
b. Total B by A operates for one complete cycle of the
Channel A signal. The stop circuit delay is available on
Channel A
1.6.3 Check Function
1.6.3.1 With the Check function selected, a number of
functional tests of the instrument’s circuits can be made
without the use of additional test equipment. Although these
tests do not check the instrument’s performance to published
specifications, they can be used to verify that the
equipment is operating correctly following receipt or
transportation to a new location. A brief, preliminary
functional check procedure is given in Subsection 2.6.
1.6.4 Input Signal Channels
1.6.4.1 Inputs A and B are fully independent. However,
provision is made for connection of the signal at the
Channel A input into both channels. This is effected by
selecting the COM(mon) A mode. When COM A is selected,
Channel B’s input socket is isolated from Channel B!s circuitry.
1.6.4.2 Inputs A and B are provided with independent
controls to permit the following selections:
a. AC or DC input coupling
b. 1MΩ or 50Ω input impedance
c. x1 or x10 input attenuation
d. Positive or negative-slope trigger
e. Manually or automatically-set input trigger level
1.6.4.2.1 The manually-set trigger level is entered as an
internal store.
1.6.4.2.2 The auto-trigger level is derived by measuring the
positive and negative peaks of the input signal. If the
peak-to-peak value exceeds 5,1V or if either peak is outside
the range + 5.1V, the x1O attenuator is automatically
switched in* The trigger level is then set to the arithmetic
mean of the measured value.
1.6.4.2.3 When operating in the auto-trigger mode, with the
x1O attenuator in circuit, the attenuator wiE be switched
out if the peak-to-peak value is less than 4,6V and both
peak values are within the range + 4.6V.
1.6.4.2.4 The trigger levels in use are available at pins
mounted on the rear panel of the instrument. The voltage
range is +/- 5.1V regardless of whether the attenuator is
switched in or not, so the voltage should be multiplied by
10 when the x1O attenuator is selected.
1.6.4.3 Input C is available on the Model
1992 only. It has
a nominal input impedance of 50ft and is AC-coupled.
Protection against excessive signal levels is provided by a
fuse mounted in the input socket.
1.6.5 Low-Pass Filter
1.6.5.1 An internal low-pass filter can be introduced to
reduce the bandwidth of Channel A to 50 kHz (nominal).
1.6.6 Math Function
1.6.6.1 When the math function is active, the displayed
value is:
Measurement Result - X Z
where X and Z are values entered into stores within the
instrument by the operator. X is set to 0 and Z to 1 when
the instrument is first switched on. By suitable choice of
values for X and Z, ratio, offset (null), and
percentage-difference displays can be obtained.
1.6.7 Special Functions
1.6.7.1 A number of special functions are available to the
operator. TTiese provide test procedures and operating
facilities in addition to those available by operation of
the front-panel controls. See Subsection 3.8 of this manual
for further details.
1.6.8 Error Indication
1.6.8.1 When operating the 1991/1992, certain errors will
result in displayed error codes. See Subsection 3.9 of this
manual for further details.
1.6.9 External Arming
1.6.9.1 External arming of the start and stop circuits for
the measurement interval can be carried out by means of
signals connected to a rear “panel mounted socket. Any
combination of internal and external arming can be selected
by using the appropriate special function. For further
details, refer to Subsections 3.8 and 3.11 along with Table
3.12 in this manual.
1.6.10 Display Format
1.6.10.1 The display uses an engineering format, with a
nine-digit mantissa and one exponent digit. Overflow of the
most significant digits can be used to increase the display
resolution.
1.6.11 Hold Feature
1.6.11.1 The hold feature allows readings to be held
indefinitely. A new measurement cycle is initiated using the
RESET key.
User manual
Manual type:
User manual
Pages:
116
Size:
3.9 MB
Language:
english
Revision:
Manual-ID:
980647
Date:
August 1987
Quality:
Scanned document, all readable.
Upload date:
Feb. 3, 2018
MD5:
22312e2e-1456-936b-0dcd-1a90f1bd6f90
Downloads:
908
Service and user manual
Manual type:
Service and user manual
Pages:
240
Size:
5.6 MB
Language:
english
Revision:
Manual-ID:
980647
Date:
August 1987
Quality:
Scanned document, all readable.
Upload date:
Feb. 3, 2018
MD5:
d987c52c-35f3-9639-695c-a087f9e947d3
Downloads:
626