GW Instek GFC-8131H User manual

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USER MANUAL
CONTENTS PAGE
1. PRODUCT INTRODUCTION............................................. 1
2. TECHNICAL SPECIFICATION…………………………... 2
3. PRECAUTIONS BEFORE OPERATION…….…………...
3-1.Unpacking the Instrument………………….…………...
3-2.Checking the Line Voltage…………………..………….
3-3.Equipment Installation and Operation………………...
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4. PANEL INTRODUCTION……………………..…………… 6
5. APPLICATION………………………………………………. 9
6. MAINTENANCE……………………………………………..
6-1.Standard Method for Calibration………………………
6-2.Cleaning…………………………………………………...
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1. PRODUCT INTRODUCTION
The intelligent counters are measuring frequency and period from
the range of 0.01Hz to 120MHz on channel A, and 50MHz to
1.3(2.7)GHz on channel B.
The products also provide special features of high resolution and
sensitivity for value reading expediency.

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2. TECHNICAL SPECIFICATIONS
CHANNEL A
Range Coupling AC DC
FREQ A 30Hz to 120MHZ 0.01Hz to 120MHz
PRID A 8ns to 30ms 8ns to 100s
Sensitivity
(rms)
50mVrms Max. to 10kHz.
25mVrms Max. to 80MHz.
35mVrms Max. to 120MHz.
(If frequency ＜10MHz, sensitivity figures are for 4
stable digits of reading.)
Coupling AC or DC switchable.
Filter Low pass, switchable in or out on channel A.
3dB point of nominally 100kHz.
Impedance 1MΩnominal shunted by less than 40pF.
Attenuator ×1 or ×20 nominal.
Trigger Level Variable between +2.5V DC and –2.5V DC.
Damage Level AC & DC ×1
DC to 2.4kHz 250V(DC+AC rms)
2.4kHz to 100kHz 600kV rms Hz FREQ
＞100kHz 6V rms
AC & DC × 20
DC to 20kHz 500V(DC+AC peak)
20kHz to 100kHz 10MV rms Hz FREQ.
＞100kHz 100V rms
CHANNEL B
Range 50MHz to 1.3GHz (GFC-8131H)
50MHz to 2.7GHz (GFC-8270H)
Sensitivity GFC-8131H GFC-8270H
25mVrms Max. to 80MHz 25mVrms Max. to 80MHz
15mVrms Max. to 700MHz 15mVrms Max. to 1GHz
25mVrms Max. to 1GHz 25mVrms Max. to 2GHz
40mVrms Max. to 1.3GHz 50mVrms Max. to 2.7GHz
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Coupling AC
Impedance 50Ω
Max. Input Level 3Vrms sine wave
General
Resolution
Gate time displays at least 7 digits for 1s, 6 digits for
100ms, 5 digits for 10ms respectively.
The maximum resolution for frequency measurement is
100nHz for 1Hz, and 0.1Hz for 100MHz input
respectively, and for period measurement is 10nS for
1Hz, 0.1fs (f=10-15 ) for 100MHz input respectively.
Time Base
Frequency------------10MHz
Aging Rate-----------1ppm per month
Temperature----------5ppm, 23℃±5℃
Line Voltage---------±0.005ppm for ±10% variation
Accuracy ±Resolution ±Time base error.
Gate Time Continuously vary from 10ms to 10s or 1 period of the
input depending on whichever is greater.
Display 8 digits and overflow indicators
Operation
Temperature 0℃~40℃
Operation
Humidity 10~80% RH
Power
Requirement 100/120/220/230±10%, 50/60Hz selectable internally.
Max. consumption power is 15VA.
Dimension Approx. 230(W) × 95(H) × 280(D) m/m.
Weight Approx. 2.0 kgs.
Accessories
Instruction manual……………× 1
Power cord……………………× 1
Test lead GTL-101 …………..× 1
GTL-110 …………..× 1

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3.PRECAUTIONS BEFORE OPERATION
3-1.Unpacking the Instrument
The instrument has been fully inspected and tested before shipping from
the factory. Upon receiving the instrument, please unpack and inspect it
to check if there is any damages caused during transportation. If any sign
of damage is found, notify the bearer and/or the dealer immediately.
3-2.Checking the Line Voltage
The instrument can be applied any kind of line voltage shown in the table
below. Please check the line voltage indicated in the label attached on the
real panel to replace correct fuses.
WARNING. To avoid electrical shock the power cord
protective grounding conductor must be connected to ground.
When line voltages are changed, replace the required fuses shown as below:
Line voltage Range Fuse Line voltage Range Fuse
100V
120V 90-110V 108-132V T200mA 250V 220V 230V 198-242V 207-253V T100mA 250V
WARNING. To avoid personal injury, disconnect the power
cord before removing the fuse holder.
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3-3.Equipment Installation, and Operation
Ensure there is proper ventilation for the vents in the case. If this
equipment is used not according to the specification, the protection
provided by the equipment may be impaired.

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4. PANEL INTRODUCTION
(1). Power ON/OFF Power on or off by using the button.
(2). Reset Restart counting by resetting counter to zero.
(3). FREQ A Select frequency mode of operation for input A.
(4). PRID A Select period mode of operation for input A.
(5) FREQ B Select frequency mode of operation for input B.
(6). Gate Time(LED) When Gate time LED is on, the counter’s main gate
circuit is open and the measurement is in processing.
(7). Gate Time(KNOB) Select variable measurement time from 10ms to 10s
continuously (minimum=1 period of the input signal).
The display value can be hold by pulling the knob until
it is pushed back.
(8). TRIG LEVEL
(LED) Indicate the input signal above or below the trigger level by setting on the TRIG LEVEL.
(9). TRIG LEVEL
(KNOB) Pull the knob, the TRIGGER LEVEL control will be
variable over ±2.5V × ATT and push the knob to
proceed auto-set function.
(10)
.LPF/ON Insert a 100kHz low pass filter into input A.
(11) ATT ×1/×20 Select attenuation for input A
×1 Directly connect input signal to input amplifiers.
×20 Attenuate input signal by a factor of 20.
(12) COUP DC/AC Select DC or AC coupling for input A.
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(13) INPUT A Input BNC for input A
(14) INPUT B Input BNC for input B.
(15) S The unit of displayed data is second (S).
(16) Hz The unit of displayed data is Hertz (Hz).
(17) Exponent (LED) Indicate the value of the measurement exponent as
shown below:
k=1000 M=1,000,000 G=1,000,000,000
m=1/1000 μ=1/1,000,000 n=1/1,000,000,000
(18) DISPLAY(LED) 8 digits red LED display.
(19) OVFL(LED) OVFL (overflow) indicator shows that one or more of
the most significant digits are not displayed.

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zFront Panel
Fig. 1 Front panel
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5. APPLICATION
(1) Signal Measurements
Frequency range between 0.01Hz and 120MHz, press FREQ A switch,
then connect input signal to the channel A input BNC.
Frequency range between 50MHz and 1.3(2.7) GHz, press FREQ B
switch, then connect input signal to the channel B input BNC.
Press “PRID” switch to select period mode of operation for signal on
input A.
(2) Gate Time Settings
The instruments features continuously adjustable gate time selection
from 10ms to 10s or one period of input, depending on whichever is
longer. The GATE TIME adjustment affects the sampling rate and the
resolution of the reading.
Turn the knob counterclockwise for updating faster reading, or turn it
clockwise for more resolution (digital display).
Pulling out the GATE TIME knob to freeze the latest displayed reading
for being written down. Then return the counter to normal operation by
pressing back the knob.
When the instrument is starting measurement, the LED indicator above
the GATE TIME knob will light. In normal operation, it will blink at a
rate setting by GATE TIME knob.
(3) Trigger Level Adjustment
Adjust the trigger voltage of channel A input signal by pulling and
turning the TRIG LEVEL knob for triggering. The trigger voltage is
variable over ±2.5V×ATT setting.
If push the knob, it can be functioned as auto-triggering.(this knob is
only available for channel A.)

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(4) LP FILTER
An unstable reading is caused from measuring noise of low frequency
signals on channel A. The LP FILTER minimizes high frequency noise,
permitting the counter to measure only the desired low frequency
component.
For more stable reading, insert a 100kHz low pass filter into the channel
A input circuit by pushing in the LP FILTER button.
(5) Attenuator
An attenuator is provided in the channel A input circuit for measuring
large signals and for providing additional overload protection.
Reduce the input signal by 20 times by pushing in the ATT button. It is
recommended that when measuring signals of unknown amplitude, this
button should be pushed in for protection. If the amplitude is too low,
the button can be released for greater sensitivity.
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6. MAINTENENCE
The following instructions are executed by qualified personnel only. To
avoid electrical shock, do not perform any servicing other than the operating
instructions unless you are qualified to do so.
6-1.Standard method for calibration
(1) Input offset voltage adjustment
Push the TRIG LEVEL knob and turn it to the central position.
Connect a 10MHz sine wave to channel A input BNC.
Adjust SVR102 and decrease amplitude of 10MHz sine (typically
20mVrms) to the minimum allowable to maintain display.
(2) Standard oscillator adjustment
Connect a standard reference frequency (10MHz, temperature stability
＜0.2ppm) to channel A input.
Adjust the GATE TIME control for 8 digital display.
Adjust SVC201 for the most accurate display of the reference
frequency.
(3) Hysteresis Bias voltage adjustment
Set the LP FILTER to ON and set the COUP to DC position. Push the
TRIG LEVEL knob and turn it to the central position.
Connect a 1Hz sine wave 30mVrms to channel A input BNC. Adjust
SVR103 to the minimum allowable to maintain display.

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6-2.Cleaning
To clean the instrument, use a soft cloth dampened in a solution of mild
detergent and water. Do not spray cleaner directly onto the instrument
because it may leak into the cabinet and cause damage.
Do not use chemicals containing benzine, benzene, toluene, xylene,
acetone, or similar solvents. Do not use abrasive cleaners on any portion of
the instrument.