EG&G ORTEC 459 Manual de funcionamiento y servicio - Página 8
Navegue en línea o descargue pdf Manual de funcionamiento y servicio para Sensores de seguridad EG&G ORTEC 459. EG&G ORTEC 459 10 páginas. 5 kv detector bias supply
Imprimir página6. MAINTENANCE AND TESTING
CAUTION
THE HIGH VOLTAGES THAT ARE PRESENT IN
THIS INSTRUMENT ARE HAZARDOUS. DO NOT,
ATTEMPT ANY ADJUSTMENTS OR
MAINTE
NANCE UNLESS YOU ARE EXPERIENCED IN
HANDLING HIGH-VOLT AGE CIRCUITS.
Test Equipment Required:
Nuclear Standard Bin and Power Supply such as ORTEC
401A/402A
Oscilloscope with sensitivity of 10 mV or better
Voltmeter with input impedance of 100
or more on
5000-V range
Schematic diagram of the 459 Detector Bias Supply
6.1. PERFORMANCE TESTS
1. Install the 459 in the 401A/402A Bin and Power
Supply.
2. Leave the High Voltage switch set at Off and connect
the 0-5 KV output to the voltmeter, set for a 5000-V range.
3. Set the High Voltage switch at On and increase the
5-turn control slowly to maximum for 5000 V. Consider
the loading effect of the voltmeter on the high-voltage
supply and observe the output voltage. For example, a
voltmeter with a 100-MJ2 input impedance will have a
50-mA current at full scale. This will cause a 100-V drop
across the 2-MJ2 internal resistance in the power supply and
the meter will read only 4900 V maximum.
4. Return the output voltage control to zero and check
the potentiometer linearity by comparing the output
voltages to dial readings at several points.
5. To check ripple and noise it is necessary to place a
capacitor that will withstand 5000 V in series with the
0-5 KV output of the 459 and to connect this to an
oscilloscope. Set the oscilloscope for a dc input and the
lowest available sensitivity until the Detector Bias Supply
output has been increased slowly to 5000 V. Then the
oscilloscope sensitivity can be increased to observe the
ripple and noise, which should not exceed 10 mV.
6.2. TROUBLESHOOTING SUGGESTIONS
1. Ensure that the proper dc input voltage is being sup
plied to the 459. It requires -1-24 V, -24 V, and +12 V. Quies
cent currents are typically +24 V, 32 mA; -24 V, 18 mA;
and +12 V, 12 mA.
2. With an oscilloscope, check carefully for a square wave
at the collectors of Q1 and 02. If no square wave is present,
replace the transistors 01 and 02.
3. Check for a square wave at the collectors of 05 and 06.
This square wave should vary in amplitude with the setting
of the output voltage control. If no variation is seen, check
07 and 08.
6.3. FACTORY REPAIR SERVICE
This instrument can be returned to the ORTEC factory for
service and repair at a nominal cost. Our standard procedure
for repair ensures the same quality control and checkout
that are used for a new instrument. Always contact Cus
tomer Services at ORTEC, (615) 482-4411, before sending
in an instrument for repair to obtain shipping instructions
and so that the required Return Authorization Number can
be assigned to the unit. Write this number on the address
label and on the package to ensure prompt attention when
it reaches the ORTEC factory.