Summary of Contents for Direct Scientific DSM-502
- Page 1 DIGITAL SURVEY METER OPERATIONS & MAINTENANCE MANUAL Direct Scientific www.drct.com tel (310) 589-0601 fax (310) 919-2981 email: sales@drct.com...
-
Page 2: Table Of Contents
WBJI DSM-502 SECTION CONTENTS ------------------------------ SPECIFICATIONS ------------------------------ DESCRIPTION ------------------------------ THEORY OF OPERATION ------------------------------ OPERATING CONTROLS ------------------------------ OPERATING INSTRUCTIONS ------------------------------ MAINTENANCE ------------------------------ PARTS LIST ------------------------------ SCHEMATICS PAGE 2... - Page 3 WBJI DSM-502 SPECIFICATIONS - APPLY TO EACH PROBE PROBE LINEARIZATION Internal Adjustments for Calibration and Dead Time Customization INTERNAL PROBE RANGE 0 – 999.9 R/hr, 0 – 999.9 kcpm. 0 – 999.9 cps, 0 – 10mSv/hr COUNT TIME 0 -2550 SECONDS IN 10 SECOND INCREMENTS...
-
Page 4: Description
The large easy to read digital LCD readout is utilized to display all relevant data in Counts, µR/hr, mR/hr R/hr & Sv units. The DSM-502 does not require any external pc boards, pc downloads etc. to calibrate and operate. All of the controls necessary to calibrate the DSM-502 with any of the probes available from Johnson are contained in the instrument. - Page 5 HIGH & LOW VOLTAGE POWER SUPPLIES Six "AA" size batteries provide the LOW VOLTAGE power for all of the DSM-502 circuitry. The batteries are connected to a positive power regulator on the POWER SUPPLY pc board designated E1. E1 converts the 9 vdc to a very stable +5 vdc.
-
Page 6: Operating Instructions
0.050 v p-p. These high voltage and gain settings are satisfactory for operation with the many probes but can produce large errors if the DSM-502 is not calibrated with the internal probe. Refer to the MAINTENANCE SECTION 6.2 for High Voltage adjustment procedure and SECTION 6.3, 6.4 for the calibration of the system. - Page 7 WBJI DSM-502 FIGURE 2 FIGURE 2 DSM -502 FRONT PANEL CONTROLS P/N 12303 REV 6 PAGE 7...
- Page 8 WBJI DSM-502 FIGURE 3 DSM -502 POW ER SUPPLY AND M AJOR COM PONENTS P/N 12291-1 REV 1 FIGURE 4 DSM -502 LCD DIGITAL PC BOARD COM PONENTS AND CONTROLS P/N 12923 PAGE 8...
- Page 9 ADJUSTING THE METER FOR CPM/CPS AND R/Sv OPERATION 6.2.1 The switches that adjust the DSM-502 for Roentgen or Sieverts are located on the LCD pc board. To access these switches remove the DSM-502 from its housing . Looking at the bottom of the instrument with the LCD at the top the CPM/CPS switch is on the left side of the LCD pc board.
- Page 10 WBJI DSM-502 ADJUSTING THE HV 6.3.1 Remove the DSM-502 from its housing. 6.3.2 Determine if the HV that is required to operate the Internal probe is correct. 6.3.3 Adjust the MAIN SELECTOR SWITCH TO RATEMETER POSITION 6.3.4 Using a small screwdriver adjust SW4 to position 6. The number displayed will be the HV on the Internal Probe.
- Page 11 WBJI DSM-502 NOTE: GM TYPE PROBE’S CALIBRATION CONSTANT MUST BE CALIBRATED IN A RADIATION FIELD THAT PRODUCES LESS THAN 15KCPM (APPROX. 1% FULL SCALE ) TO PREVENT INTERACTION WITH THE DEAD TIME ADJUSTMENT. SCINTILLATION TYPE PROBES CAN BE SET IN FIELDS THAT ARE SOMEWHAT HIGHER DUE TO THE LOWER DEAD TIME OF SCINTILLATION PROBES.
- Page 12 The survey meter is now ready for NORMAL OPERATION. ADJUSTING ALARM SETPOINTS GENERAL: THE DSM-502 HAS AN AUDIBLE ALARM THAT CAN BE SET INDEPENDENTLY FOR RATEMETE DOSE, RATEMETER CPM & COUNTS. THE SAME CONTROLS SW4, SW5, P1 & P2 ARE UTILIZED TO MAKE THESE ADJUSTMENTS.
- Page 13 Return SW4 to the 0 (ZERO) POSITON FOR NORMAL OPERATION TIMED COUNT GENERAL: THE DSM-502 HAS A TIMED COUNT FUNCTION AND CAN BE SET INDEPENDTLY FOR EACH PROBE. THE RANGE OF THE TIMED COUNT IS 0 – 2550 SECONDS IN 10 SECOND INCREMENTS. THE TIMED COUNT FUNCTION IS ONLYAVAILABLE FOR THE PROBE IN THE COUNT POSITION OF THE MAIN SELECTOR SWITCH.
- Page 14 WBJI DSM-502 6.9.11 If the instrument remains ON a new count cycle can be started by DEPRESSING THE ZERO SWITCH on the front panel for at least 3 seconds PAGE 14...
-
Page 15: Parts List
WBJI DSM-502 PARTS LIST PAGE 15... - Page 16 WBJI DSM-502 7.0 PARTS LIST 7.1 DSM-502 LCD PC BOARD -- P/N 12472 JOHNSON P/N DESCRIPTION REFERENCE QUANTITY REQUIRED ****************************************************************************************** 12923-1 LCD DRIVE BRD REV-1 116200 I.C 4Kb FRAM SERIAL MEMORY 116199 I.C. 80 PIN FLASH MICRO CONTROLLER 105291 SWITCH ON-OFF-ON...
- Page 17 DIODE SCHOTTKY 30V 30 ma D1,4,6,7,8, 112341 RESISTOR 249K 1% R25,51 112426 RESISTOR 120 OHM 5% 112452 SOCKET 10 PIN 7.3 DSM-502 LOGIC BOARD -- P/N 12472 JOHNSON P/N DESCRIPTION REFERENCE QUANTITY REQUIRED ************************************************************************************************ 112948 2.5 X2MM RED LIGHT LED 1,2,3,4,5,6...
- Page 18 WBJI DSM-502 12929-1 PC BOARD W/LCD SUP 9021-3 SPEAKER GASKET DIE #518 9077-4 ROTARY SWITCH MOD 103742 7.4 DSM-502 POWER SUPPLY BOARD -- P/N 12291 JOHNSON P/N DESCRIPTION REFERENCE QUANTITY REQUIRED 100231 51K 1/8W 1206 PKG 100242 0.01MF 50V 1206 PKG...
-
Page 19: Schematics
WBJI DSM-502 SCHEMATICS PAGE 19... - Page 20 WBJI DSM-502 PAGE 20...
- Page 21 WBJI DSM-502 PAGE 21...
- Page 22 WBJI DSM-502 PAGE 22...
Need help?
Do you have a question about the DSM-502 and is the answer not in the manual?
Questions and answers