User Manual - Far West Technology, Inc.
Contents
1. LINE DVR 1 EA U3 7432N QUAD OR 1 EA U4 74156 3 to 8 DECODER l EA U5 P8212 ADDRESS LATCH nte 1 EA U6 T4LS14N HEX INV SCH TRIGGER 1 EA U7 2716 EPROM program HP 1 EA U8 P8156 RAM 10 nte 1 EA U9 74L08N QUAD AND 1 EA U10 7406N HEX INV 1 EA U11 P8253 5 16 DEC COUNTER nte 1 EA U12 7400N QUAD NAND l EA U13 8279 5 KEYB DI SPL INTERFACE nte 1 EA U14 C4040BCP BINARY DIVIDER OT 3 EA U15 16 17 6N139 OPTO ISOLATOR H P 1 EA U18 8211 VOLTAGE DETECTOR ntersi 1 EA VR2 78L12CP 12V reg 5 OT 3 EA Q1 2 3 2N6121 NPN PWR trans 2 EA 2 4 7 REK SPDT TTShadow 1 EA 53 MTA106D SPST switch pcmt Al co 2 EA 545 6 230065G 5 pos rot SW EECO 8 EA 8 to 15 210002G BCD switch 0 9 EECO 1 EA 1 609 3428 34 Pin Header Ansley 1 EA 3 03 09 2092 10 cond connector Mol ex 1 EA 3 03 09 1093 10 cond connector Mol ex RAM CHASSIS PARTS LIST QTY REQ UNIT DRAWING NUMBER PART NUMBER DESCRI PTI ON MFG 1 EA LC1 Line cord with C2F attached or 1 EA LCIA 3 wire cord with C2F attached 1 EA LF1 1B1 Line Filter Corcom l EA F4H 342014 Fuse holder panel Bussman i EA F4 AGC 3 Fuse 1 EA F1 to F3H 3823 3 3 pole fuse holder Bussman 1 EA Fl MDL 1A Fuse AL EA F2 AGC 3A Fuse 1 EA F3 AGC 3A Fuse 1 EA PS1 HBAA 40W Power supply POWER 1 1 EA JIM 7595 twist lok M chassis Hubbel 1 EA JIF 1593 twist lok F cable Hubbel l EA J 2M M53108A20 27P 14 pin 20 RA Cannon 1 EA J 2M MS3057 12A Cannon with bushing l EA J 2F MS3102A20 2758 14 pin box 20 Cannon 1 EA C4 609 3428 34 pin pcmt str2. left lug which is a chassis ground MODEL 2010 Area Monitor INSTRUCTION MANUAL PAGE 9 Health Physics Instruments The 15 lug binding post strip is for the signal connections Starting from the far left the sequence is LUG LETTER COLOR FUNCTION TO No 1 A BLK GRN GROUND HEAD UNIT amp SHIELD 1 A DOOR INT SW RETURN 1 A HORN RELAY RETURN 1 A LIGHT RELAY RETURN 1 A INTLK RELAY RETURN 2 B WHT RADF HEAD UNIT 3 C BLK WHT RADF HEAD UNIT 4 D GRN MALFP HEAD UNIT 5 E RED 24V HEAD UNIT 6 F BLK RED 24V HEAD UNIT 7 G DOOR INTLK SWITCH 8 H HORN RELAY 9 l LIGHT RELAY 10 J INTLK RELAY 11 K No connection 12 L No connection 13 M RS 232 SIG To Console 14 N RS 232 GND To console 15 SHIELD To console Note The plug letter refers to the pin letter on the MS type plugs to the RAM unit and the Head unit The colors apply to the cable Belden 9503 After installation of the brackets replace the cover plates hang the units on the brackets and plug them in The RAM unit should be adjusted at the most convenient angle for viewing The Head unit is equipped with setscrews that match holes in the bracket to hold it vertically The setscrews can be unscrewed from the enclosure into the bracket holes Tighten the hand screws firmly To replace the RAM to Head cable use Belden type 9503 shielded cable or equivalent and connector type MS 3102A2027
3. locally at the remote alarm location The driver circuit is wired in a fail safe configuration that is a Signal must be present at the relay for a no alarm condition The remote alarms may be operated in the same fashion as the RAM unit alarms and respond to the predetermined interruption rate or may be operated continuously independent of the RAM unit interruption rate setting This requires a hardware change but is necessary if a rotating beacon is used as the visible alarm MODEL 2010 INSTRUCTION MANUAL PAGE 7 Area Monitor Health Physics Instruments Please consult the factory if you need this change The visible and audible remote alarms are independently controllable C REMOTE DETECTOR SYSTEMS In high radiation environments it is necessary to remote the detector in order to avoid radiation damage to the electrometer and voltage to frequency converter In this case the detector is mounted on the same enclosure and bracket as the Head unit The detector is cabled to a duplicate of this enclosure containing the electronics mounted in a low radiation environment with a low noise coax cable and a collection voltage coax cable The cables are connected to the enclosures with BNC and MHV connectors The cabling from the electronic enclosure is the same as in the standard units To prevent microphonic response from cable motion it is advisable to run the coax cables in a conduit if applicable Low noise cable such as Essex 21 537 with BNC Teflo
4. sent to the console This switch should only be used during calibration or at other times when the audible alarm and print MODEL 2010 INSTRUCTION MANUAL PAGE 8 Area Monitor Health Physics Instruments command are undesirable To provide a status board indication that this switch is in the TEST position the yellow MALF status light comes on but the green OK light remains on D SETTING MODE The mode of operation desired is controlled by hard wire jumpers marked MODE in the upper right hand section of the microprocessor board For monitors to be used outside a radiation area the proper mode is designated O If a switch replaces the jumpers the O and 1 designations correspond to the switch positions In this mode the monitor will activate both alarms any time the preset radiation level is reached or exceeded Mode 1 is used when the detectors are inside the radiation area and the audible alarm is activated only when a controlling door interlock is open In Mode 1 the visible alarm is activated any time the radiation level reaches or exceeds the preset level For operation in both modes a relay driver is provided which can be used in an interlock circuit to turn off a source of radiation or a machine if unsafe conditions exist The truth table for all the variables is lt lt lt RAD HIGH gt gt gt lt lt lt RAD LOW gt gt gt DOOR MODE an LIGHT HORN INTRLK LIGHT HORN INTRLK closed 0 dis off off set on of
5. I 104 5 x 10 09 ohm ELTEC 1 EA R2 89PRI 00K 100K pot Beckman 1 EA R3 89PR20K 20K pot Beckman 1 EA R4 24K 5 1 4W CF epco TEA R5 1K 5 1 4W CF epco 1 EA R6 50K 5 1 4W CF epco 1 EA R7 3 3K 5 1 4W CF epco 1 EA R8 10 ohm 5 1 4W CF epco 1 EA RI 820 ohm 5 1 4W CF epco 1 EA R10 dependent on PWR SUPPLY 1 EA C1 SXK series 10 pf to 10000 pf allory 5 EA 2 5 8 9 12 C320C104KM5 l uf ceramic U CAR 1 SEA C3 5XK333 300 pf poly allory 1 EA C4 5X210 1000 pf poly allory 1 EA C6 7 TDC685MO50FL 15 uf 25 VDC tant allory 3 EA C10 11 13 TT25X150 150 uf 25VDC allory 1 AEA U1 3430 Var Electrometer Burr Brown C2800 Socket BurrBrown 1 EA U2 VFC 32KP V F connector BurrBrown 1 EA U3 DS8830N Line Driver ationa 1 EA U4 6N139 opto iso H P 1 EA U5 LM7815CT 15V reg ationa 1 EA U6 LM7915CT 15V reg ationa 1 EA U7 LM7805CT 5V reg ationa 1 EA HVPS PMT20A N opt 3 2KV PWR SPLY Bertan 1 EA D1 1N914 di ode 2 EA D2 3 1N4004 diode 1 53102A20 27 20 14 pin MS con AMPH 2 250 22 30 170 22 pin card edge con Cinch 3 143 012 01 12 pin card edge con AMPH 2 FA THM6073 heat sink 2 FA 105 0851 001 connector Johnson 2 FA 14 2010 1027 elect cover HP 2 EA 14 2010 1026 HVPS mount HP 1 EA 14 2010 1025 elect shield HP 1 EA 14 2010 1022 det encl bottom HP 1 EA 14 2010 1023 det encl cover HP 1 EA 14 2010 1024 wall bracket HP 1 EA 820 lug post R1 C1 MTG HH Smith 1 EA 21 2010 004 ribbon cable HP MODEL 2010 13 Area Monitor INSTRUCTION MANUAL ACESS
6. INSTRUCTION MANUAL MODEL 2010 AREA MONITOR Sept 1999 Version 2 Health Physics Instruments 330 South Kellogg Ave Suite D Goleta CA 93117 805 967 8422 Division of Far West Technology FUSES Power MDL 1A Others 3AG 3A MODEL 2010 INSTRUCTION MANUAL PAGE 1 Area Monitor Health Physics Instruments TABLE OF CONTENTS l GENERAL DESCRIPTION ccccccccssssssseeeeseeeeesneseneeeeseeeesaneesnaeesseeeesanesssaeeeseeeesaneesseeeeeeeennnnees 2 ll HEAD UNIT 2 lll RAM UNIT 3 A GENERAL 3 B RAM UNIT FUNCTIONS 4 IV ADDITIONAL UNITS a A NAN EE na ep nara E 6 A SLAVE DISPLAY UNIT 6 B REMOTE ALARMS 6 REMOTE DETECTOR SYSTEMS 7 C V OPERATION 7 A TURN ON PROCEDURE 7 B SETTING ALARM LEVEL 7 C SETTING ALARM CONTROLS 7 D SETTING MODE 8 Vi INSTALLATION 11111 a 8 Vil CALIBRATION AND TESTING 1111111 aaa 10 A TESTING OF RAM UNIT 10 B RADIATION CALIBRATION 10 VIII MAINTENANCE 1111 Aa 10 IX PARTSLIST 11 MODEL 2010 INSTRUCTION MANUAL PAGE 2 Area Monitor Health Physics Instruments I GENERAL DESCRIPTION The HPI Model 2010 Remote Area Monitor System RAMS measures penetrating radiation with an ionization chamber detector an electrometer and a microprocessor controlled digital circuit which presents the dose rate in digital format activates the alarms generates digital signals for transmission to a central console and performs an internal check on the operation of the monitor every up da
7. ORY PARTS LIST TY consists of 1EA SPARE PARTS LIST The following items are recommended for Level parts replacement the instrument on two levels level and level 2 is a component LEVEL1 QTY REQ UNIT PART NUMBER 1 EA 17 2010 110000 1 EA 17 2010 509120 1 EA 17 2010 713300 1 EA HBAA 40W 1 EA 3430 1 EA 2010 5 1 EA PMT20A N OPT3 5 EA MDL 1 5 EA AGC 2 LEVEL2 ALL U s from parts list ALL D s from parts list ALL Q s from parts list 2 EA 1 EA X70 W06 12 EA 259 12 EA 194 10 EA LR 1723R PAGE Health Physics Instruments Q REQ UNIT DRAWI NG NUMBER PART NUMBER DESCRI PTI ON FG 1 EA 21 2010 001 connector cord from RA o mounting bracket for 110VAC 1 EA 21 2010 002 connector cord from RA o mounting bracket for signal 1 EA 21 2010 003 5 connector cord from RA mounting bracket o head 5 long 1 EA 21 2010 003 XX connector cord from RA mounting bracket o head XX long Specify ength 1 EA 21 2010 004 see head ribbon cable listing 1 EA 21 2010 005 Connector cord from RAM to head For calibration or stand alone use 27 12A with bushing de n wire spare parts to maintain 1 is a plug in replacement level DESCRI PTI ON M COMPUTER BOARD WITH WIRING HARNESS H DISPLAY BOARD COMPLETE H V F BOARD COMPLETE H Power Supply P ELECTROMETER B DETECTOR H HV POWER SUPPLY B Fuse B Fuse B GLASS PANEL FRONT H HORN P LI GHT BULB S LI GHT BULB G 1 7SEG DIGITAL DISPLAY
8. S with MS 3057 12A with bushing For cable lengths up to 100 feet connect the colored wires to the plug letters A B C D E and F according to the above table Do not connect the shield Jumper pins A and N in the plug At the mounting bracket use either solder or crimp lug terminals and connect the colored wires to lugs 1 2 3 4 5 and 6 according to the above table and the shield to lug 1 For distances greater than 100 feet omit the jumper in the MS connector and connect the cable shield to pin M The cable from the RAM to the console is Belden type 9182 At the bracket the shield is connected to lug 15 the black wire to lug 14 and the colored wire to lug 13 using terminal lugs MODEL 2010 INSTRUCTION MANUAL PAGE 10 Area Monitor Health Physics Instruments Vil CALIBRATION AND TESTING A TESTING OF RAM UNIT The RAM unit has a built in pulse generator which is controlled by the crystal oscillator This oscillator is set for 1000 Hz When the TEST push switch in the upper right hand corner of the microprocessor circuit board is depressed the oscillator is connected to the input of the read out circuit The display should show 1000 disregard the decimal point after a complete up date period if the RAM unit display is functioning properly B RADIATION CALIBRATION Local radiation calibration procedures are usually developed depending on the sources and facilities available Using a cobalt 60 or cesium 137 source the following procedure
9. f Off closed 0 norm off off set on on Off closed 1 dis off off set on off set closed 1 norm off off set on on set open 0 dis off off off on off Off open 0 norm off off off on on Off open 1 dis off off off on off Off open 1 norm off off off on on Off Notes ALM DIS refers to the alarm disable toggle switch in the upper right hand corner of the microprocessor circuit board INTRLK refers to the interlock circuit controlling the radiation source Mode 2 and 3 are the same as 0 and 1 respectively if the RAM is not equipped with a tripset VI INSTALLATION The wall bracket for the RAM unit will have three cables attached as it is received Remove the cover plate from the RAM mounting bracket The three 1 4 holes in the rear are for mounting Firmly mount this bracket and the Head unit bracket to the wall with screws or lags Either electrical conduit or cables can be led directly into the top of the RAM mounting bracket and the wires attached to the binding post strips The power strip is the three lug strip on the right If three wires are used when installing the power input follow the color code of the cord leading to the RAM unit by matching the green white and black leads The green ground lead is grounded in the enclosure and should not be grounded to the bracket If only two wires are used and the conduit is considered ground match the white and black leads and move the green lead from the RAM unit to the furthest
10. ficant digit the MALF light will come on and the monitor will be reading low in the right hand digit This condition can be quickly corrected by turning the RAM off removing the front cover of the head unit removing the small cover plate at the detector end of the enclosure and blowing warm not hot air with a hot air gun or hair dryer into the volume with the high impedance circuit and ceramic feed through Replace the small cover and MODEL 2010 INSTRUCTION MANUAL PAGE 11 Area Monitor Health Physics Instruments turn the RAM on and wait a few minutes for a steady zero reading Adjust the zero if necessary and replace the desiccant Then replace the outer cover IX PARTS LIST COMPUTER BOARD PARTS LIST TY Q REQ UNIT DRAWING NUMBER PART NUMBER DESCRI PTI ON FG 1 EA R1 89PRIMEG 1 meg pot Beckman 1 EA R2 51K 5 1 4W CF epco 1 EA R3 3 meg 5 1 4W CF epco 1 EA R4 1K 5 1 4W CF epco 1 EA R5 3 3K 5 1 4W CF epco 16 EA R6 to 21 24 1K 5 1 4W CF epco 2 EA R22 23 180 ohm 5 1 4W CF epco 1 EA R25 390 ohm 5 1 4W CF epco 3 EA Cl 2x3 TAC225K025P03 2 2 uf 25VDC tant allory 2 EA C4 5 C320C10425U1EA 1 uf disc ceramic U CAR 1 EA C6 TAC226K010P04 22 uf 10VDC tant Sprague 25 EA FC C320C104Z5U1EA 1 uf disc ceramic U CAR 33 EA DI 8 to 39 1N914 diode 3 EA D2 3 7 TIL209A LED red T 3 4 T 3 EA D4 5 6 1N4004 diode ir 1 EA YI P 061 6 144 MHZ XTAL Crystek 1 EA U1 P8085A MI CROPROCESSOR 1 EA U2 DS1488N RS 232
11. he bracket to an MS type connector in the rear of the RAM unit By removing the two connectors from the rear of the RAM unit the entire unit may be easily disconnected and removed from the system for calibration or servicing The circuit of the RAM unit contains the microprocessor for controlling the various functions These functions will be discussed in the following sections Some of the functions may be omitted in any particular monitor depending on its use but any of the functions can easily be added to existing monitors Also three function switches may be replaced with jumpers These appear in the upper right section of the microprocessor circuit board and are designated UNITS RANGE and MODE In this manual these will be referred to as jumpers but switches could replace the jumpers to obtain a monitor to be used for different purposes MODEL 2010 INSTRUCTION MANUAL PAGE 4 Area Monitor Health Physics Instruments elol olojo oloo 2 TRIPSET Hr R ng 25 z ee 458455 lt 3 ea AGCS CA MDL1 FUSE bs o FUSES Ca UH POWER ON OFF Q TE DETECTOR RAM UNIT HEAD UNIT Figure 2 Location Of Controls B RAM UNIT FUNCTIONS 1 DISPLAY FUNCTION The do
12. ing from 1 to 100 000 Hz This signal is sent to the microprocessor circuit by a multiwire connecting cable through an MS type connector in the top of the Head unit No external controls are available at the Head unit but two internal controls are used to set the zero of the electrometer and the overall sensitivity of the unit The sensitivity of the unit is set so that 1 Hz corresponds exactly with a 1 in the least significant digit of the read out display The Head units are thus interchangeable with other RAM units of the same range The Head units for different ranges employ different feedback resistors The high impedance circuit on the base of the electrometer consisting of a feedback resistor and a time constant capacitor is shielded from the rest of the circuit and the collection voltage The collection voltage power supply is a self contained variable voltage supply which is factory set at 1000 volts At this voltage 90 collection efficiency is obtained for all chambers at the highest dose rate to be measured The voltage to frequency converter and its associated power supplies and line drivers are mounted on a plug in circuit board MODEL 2010 INSTRUCTION MANUAL PAGE 3 Area Monitor Health Physics Instruments RESPONSE 10 100 1000 KEV Figure 1 Energy Response of Model 2010 TE lonization Chamber 1031 Cc lll RAM UNIT A GENERAL The RAM unit is housed in an aluminum enclosure with a glass window in front of the dis
13. ip con Ansley 1 EA CABI cable consists of 2 EA 609 3430 connector mass term Ansley 1 FT 34 cond cable Ansl ey 2 EA 609 3431 cable strain release Ansley MODEL 2010 INSTRUCTION MANUAL PAGE 12 Area Monitor Health Physics Instruments 1 EA 609 3428 34 pin connector Ansley 1 EA Printed Circuit Board DISPLAY BOARD PARTS LIST QTY REQ UNIT DRAWING NUMBER PART NUMBER DESCRI PTI ON FG 13 EA R1 8 R25 29 3 3K 1 4W 5 CF epco 20 EA R9 24 R41 44 1K 1 4W 5 CF epco 8 EA R45 52 15 ohm 1 2W 5 CF epco 6 EA R35 40 180 ohm 1 4W 5 CF epco 1 EA C1 TVA1207 5 150 uf 25VDC Sprague 2 EA C23 C320C104Z5U1EA l uf ceramic U CAR 1 EA D1 TIL 209 A red 3 4 LED T 1 EA D2 TIL 228 1 red 1 3 4 LED T 3 EA D3 5 7 TIL 234 2 green 1 3 4 LED T 2 EA D4 6 TIL 240 1 yellow 1 3 4 LED Te 9 EA Q1 8 29 2N3392 NPN sig trans G E 13 EA Q9 16 18 20 2N6125 PNP pwr trans FAIR 22 24 26 5 EA pala lae1 2N6067 PNP sig trans G E 25 2 EA Q27 28 2N6121 NPN pwr trans MOT 1 EA Ul 7407 hex buff HV NAT 2 EA U2 3 7406N Hex O C Invert NAT 5 EA D51 5 LR1723R 1 7 seg red display IEE 1 EA HORN X70 W06 horn Project Design 1 EA LI GHT 106R light Peterson qe BA 259 Light Bulb for light SYLVAN 1 EA 194 Light bulb for light GE 2 FA 15 2 MPA106F SPST push mom Al co 1 EA 3 MPA206R DPDT push mom Al co 1 BA JI 609 3428 34 pin PC connector Ansley HEAD PARTS LIST QTY REQ UNIT DRAWING NUMBER PART NUMBER DESCRI PTI ON FG 1 EA R
14. is suggested for calibrating the monitor at a calibration facility Remove the front of the Head unit Two adjustments are available on the circuit board With the detector in a down position the upper adjustment is sensitivity and the lower one zero set Set the unit in a background radiation field and set the zero by first adjusting it to read 1 in the least significant digit and then turning the adjustment until the reading is just zero To set the sensitivity of the most sensitive units XXXX X mrad h set the Head unit in a known field of radiation of approximately 1000 mrad h Set the sensitivity control to match the known dose rate This will have to be done using successive adjustments with the operator making the adjustments only with the source shielded It should be noted that the Head unit is the variable the RAM units all have the same sensitivity Thus any Head unit can be calibrated on any RAM unit for use on any other RAM unit After setting the sensitivity set the Head unit in a field of between 4000 and 5000 mrad h and observe the read out Set the Head unit in a field of between 8000 and 9000 mrad h and observe the read out Readings a few percent low may occur due to incomplete collection at high doserates but should not exceed 10 Set the Head unit in a field in excess of 10000 mrads h to observe the overflow indication If it is desirable to calibrate the Head unit and the particular RAM unit which is used with that detector
15. it is suggested that a separate power cord and a separate cable with MS type connectors be made up so that the wiring in the RAM mounting bracket can stay in place See Accessory parts list If calibrations are to be performed in place a local shielded source can be used in a manner in which the source detector geometry is reproducible High radiation level readings may be difficult to attain in this manner but the calibration of the lower part of the range would be valid If calibrations are performed in place the alarm disable switch in the upper right corner of the microprocessor circuit board may be switched from NORM to TEST to quiet the audible alarms It should be noted that in this condition no print command will be sent to the console Vill MAINTENANCE The only periodic maintenance required is replacing the desiccant in the detector housing if necessary Remote read out units installed in high radiation environments may require new cables and or red plastic filters if the accumulated total dose becomes too great The outside face of the viewing window is glass and should be cleaned periodically If the Head unit is subjected to very high humidity for extended periods and the desiccant is bad the ceramic feed through insulator make leak slightly If this condition arises the leakage will be downscale that is in a direction that will try to make the RAM read negative radiation If this reading becomes approximately 5 in the least signi
16. its range and mode codes 3 The status board data consists of 2 bytes Byte 1 Upper 4 bits are always 0100 Bit 1 2 and 3 not used Bit 0 H overrange Byte 2 Upper 4 bits are always 0100 Duplicates the front panel LED s Bit O H High radiation LED on Bit 1 H low radiation LED on Bit 2 Malfunction LED on Bit 3 OK LED on IV ADDITIONAL UNITS A SLAVE DISPLAY UNIT The RAM unit may be equipped with a Slave Display unit that duplicates the display and the status board The enclosure and mounting bracket are duplicates of the RAM unit enclosure and mounting bracket but the enclosure contains no electronics A multiwire cable connects the Slave Display unit with the RAM unit The cable goes through the bracket at the Slave Display unit and is connected to the Slave Display unit through the binding post strip and a D type connector on the rear of the enclosure At the RAM unit the cable does not go through the bracket but plugs directly into the rear of the enclosure The RAM unit for systems equipped with a Slave Display unit contains an additional circuit board to drive the Slave Display unit B REMOTE ALARMS Remote alarms may be driven from the RAM unit The RAM unit contains the drivers for relays to operate the remote alarms The relays to operate the remote alarms may be mounted in either the base of the alarm or in the RAM mounting bracket 110VAC for the remote alarms is either supplied from the bracket power lugs or obtained
17. larity so as to simulate a radiation pulse This pulse cannot be applied to the chamber if the collection voltage power supply fails The electrometer responds to this pulse as a pulse of radiation and its output is converted to a number of digital pulses by the voltage to frequency converter The microprocessor reads the number of pulses and if none or too few occur the malfunction light comes on After the test the counters are unlatched and normal operation is resumed None of the status board functions are latching All status board information is transmitted to the central console 4 MODE FUNCTION The Mode determines which type of monitor is required the detector outside the radiation area sensing any radiation leakage through the shielding or the detector inside the radiation area sensing whether the radiation is high and the door interlocks are closed If they are open an unsafe condition exists the alarms are activated and the radiation source would be deactivated Mode 1 designates that the system is set up for the detectors inside the radiation area Mode 0 designates that the system is set up for operation with the detectors outside the radiation area The general operation is as follows Mode 0 detectors outside the area Radiation low Door closed no alarms Radiation low Door open no alarms and machine interlock relay driver in off condition Radiation high Door closed visual and audible alarms and or open machine interl
18. ls the light alarm and the upper the audible alarm Positions 4 3 and 2 provide different rates of interrupted alarms with position 4 being the fastest and position 1 provides a steady alarm Do not set on 0 since this could turn the alarms off The visible alarm contains two 12 volt lamps One is a long life low intensity lamp and the other is a high intensity relatively short life lamp If one lamp burns out it is suggested that both be replaced 3 STATUS BOARD FUNCTION The status board contains a maximum of six LEDs to show if radiation high above trip level or radiation low below trip level conditions exist if the door interlock is open or closed and if the monitor is OK or malfunctioning The red RADIATION HIGH light comes on any time the trip level is exceeded otherwise the green RADIATION LOW light is lit The yellow DOOR OPEN light comes on when the interlock switch on a controlling door is open otherwise the green DOOR CLOSED light is lit This circuit may be used to control additional alarms or to control the radiation producing device see MODE FUNCTION below The yellow MONITOR MALF malfunction light comes on any time the monitor fails to pass the automatic internal test otherwise the green MONITOR OK lamp is lit The internal test consists of the following sequence of events which occur every update period The display is latched at the end of the update period A small pulse is applied to the collection voltage of a po
19. n connectors must be used for the signal lead RG 59U with MHV connectors can be used for the high voltage cable V OPERATION A TURN ON PROCEDURE The power toggle switch is located in the lower right corner of the RAM unit The power fuse that is mounted beside it should be a type MDL 1 Amp fuse The three fuses mounted in the fuse block on the power supply protect the low voltage power supplies They should be type AGC 3 Amp fuses When the instrument is first turned on or immediately following any power interruption the RAM will go through a wait procedure that requires 20 seconds During this period no numerals will appear but the decimal point will be lighted and the door interlock status lights if supplied will function properly The initializing procedure can be duplicated by pushing the RESET switch on the top right of the circuit board in the RAM unit This switch is the reset for the microprocessor Do not plug in any units while the power is on f the Head unit is not connected to the RAM unit the MALF light will come on B SETTING ALARM LEVEL Five thumb switches mounted in the upper left hand edge of the microprocessor board in the RAM unit correspond to the five display digits The most significant digit is marked MSD and the least significant digit is marked LSD The preset trip level is set into the circuit by setting these switches to the desired numbers The alarms will be activated if only zeros are set in This preset le
20. nit by five thumb switches mounted inside the enclosure along the upper left hand edge of the circuit board The trip level setting can be observed at any time by pushing the exterior TRIPSET switch Pushing this switch replaces the doserate display with the five digits of alarm trip level The alarms may be tested at any time by pushing the external TEST switch This switch activates only the alarms and not the circuits controlling them Another TEST push switch which may be used to test the alarm circuit is inside the enclosure This switch places 1000 regardless of the decimal point location into the read out If the trip level is set below 1000 the alarms will be activated Note that this switch also tests the read out MODEL 2010 INSTRUCTION MANUAL PAGE 5 Area Monitor Health Physics Instruments During calibration or other periods when the audible alarm is not desired the alarm disable toggle switch in the upper right hand corner of the circuit board may be moved from the down position NORM to the up position TEST The visible alarm will still be functional but the audible alarm will be silenced and no print command will be sent to the console Note that when this switch is in the TEST position the malfunction light will come on and if the RAM is operating properly the green OK light will also be lit Two screw driver adjustable rotary switches to vary the frequency of the alarms are provided on the circuit board The lower switch contro
21. ock relay driver in off condition Mode 1 detectors inside the area Radiation low Door closed no alarms Radiation low Door open no alarms and machine interlock relay driver in off condition Radiation high Door closed light alarm only Radiation high Door open visual and audible alarms and machine interlock relay driver in off condition Setting the alarms is covered in section V D If the door is not used and no connection is to the terminal strip then the door is open MODEL 2010 INSTRUCTION MANUAL PAGE 6 Area Monitor Health Physics Instruments 5 INTERNAL LED INDICATORS Three red LED indicator lights are provided on the top right side of the microprocessor circuit board From right to left they are marked INTLK PRINT TEST They indicate the following INTLK Opposite to the interlock circuit for controlling the radiation source This light is lit when the monitor is preventing operation of or shutting down the source of radiation PRINT This light is lit when a print command is being sent to the console which occurs when there is a tripped condition TEST This light is lit when the Head unit is properly cabled It will dim at high doserates 6 DATA TRANSMISSION TO THE CONSOLE The RAM unit microprocessor circuit transmits the following data to the console on the RS232 data line The baud rate is 9600 No parity 1 stop bit O The five digits of doserate 1 The five digits of trip level setting 2 The un
22. play The unit consists of the microprocessor circuit board display circuit board low voltage power supplies and alarms The enclosure front is hinged and is key lockable The only controls available outside the locked enclosure are the alarm TEST and the TRIPSET trip level display push switches All other controls are mounted inside the enclosure behind the locked door Figure 2 shows the location of all the internal controls Power for the entire monitor comes from the RAM mounting bracket The power switch and the power fuse are mounted behind the locked door in the lower right hand corner of the enclosure The wall mounting bracket for the RAM unit permits the unit to be swung at an angle from the horizontal The bracket contains the connection strips to the rest of the monitor and to the 110VAC power Electrical conduit may be led into the top of this bracket and connected to the monitor through a binding post strip The RAM unit power from a twist lock plug in the back of the RAM unit is connected to the bracket by a cable entering the bottom of the bracket Other connections which must be made to the RAM unit are the cable from the Head unit the twisted pair to the central console the door interlock and the horn light and interlock relays The cables from these external units enter the top of the bracket and fan out to a binding post strip The connection to the RAM unit is made with a cable from the binding post strip through the bottom of t
23. serate is displayed as a five digit array of one inch red LEDs mounted behind a red plastic filter The decimal point can be placed as follows XXXXX XXXX X XXX XX or XX XXX and the units can be mrad h rad h or krad h depending on the detector and the Head unit The highest sensitivity monitor has the display XXXX X mrad h The decimal point location and the units can be changed by changing the jumpers in the upper right hand section of the microprocessor circuit board marked RANGE and UNITS The units jumpers are only used to transmit the units information to the central console The display updates displays new data approximately every 3 seconds and flashes to indicate the update period The display circuit automatically blanks all left hand zeros to the left of the decimal point except the one immediately preceding the decimal point and automatically presents a maximum of three digits of significant data by changing the fourth and fifth digits to zeros The highest indicated reading is therefore 99900 If the radiation level exceeds the range of the monitor an over range signal will be displayed This signal is a rapid flashing of 99900 2 ALARM FUNCTION Audible and visible alarms are mounted on the front of the RAM unit These alarms are activated if a preset level of doserate is reached or exceeded and are not latching If the radiation level falls below the preset level the alarms are deactivated The preset doserate is entered into the u
24. te period The basic Remote Area Monitoring System consists of two enclosures One is the Head unit which contains the tissue equivalent ionization chamber detector high voltage power supply electrometer and digitizer This enclosure is cabled to the RAM unit which contains the microprocessor circuit the low voltage power supplies for the electronics the five digit LED read out the status board the visible alarm the audible alarm and the circuit for transmitting the data to a central console The monitor is powered by 110VAC 60 Hz at the RAM unit ll HEAD UNIT The detector is a tissue equivalent ionization chamber made of Shonka A 150 TE plastic walls and filled with TE gas The chamber is mounted on the external surface of the enclosure and is sealed at approximately one atmosphere pressure The volume of the chamber depends on the sensitivity of the monitor XXXX X mrad h and XXXXX mrad h ranges employ 1031 cc chambers the XXXX X rad h range employs a 50 cc chamber and the XXX XX krad h range employs a 6 cc chamber The energy response of the 1031 cc chamber is shown in Figure 1 The collection voltage of 1000 volts is generated by a DC to DC converter The ionization current is measured with a varactor bridge electrometer operated in a feed back circuit For the 1031 cc chamber the current is 2 x 10 14 A for 0 1 mrad h The output of the electrometer O to 10 volts is changed to a digital signal by a voltage to frequency converter operat
25. vel may be verified by pressing the TRIPSET push switch on the front of the RAM unit The preset level will then be displayed in place of the doserate but the left hand zeros will not be blanked C SETTING ALARM CONTROLS The alarm interrupt rate is set by two screwdriver adjustable switches in the center portion of the microprocessor circuit board The lower one marked S6 controls the light and the upper one marked S5 controls the horn Position 1 on the switch produces a steady alarm signal position 2 produces a one second interrupt signal position 3 produces a 1 2 second interrupt signal and position 4 produces a 1 4 second interrupt signal The audible and visual interrupt signals are independent DO NOT USE POSITION 0 The local alarms may be tested by pushing the TEST push switch on the front of the RAM unit This tests only the alarms and not the alarm circuit To test the alarm circuit the internal switch in the upper right hand corner of the microprocessor circuit board marked TEST is pushed This switch puts 1000 in the display regardless of decimal point setting and if the trip level is below this value the alarms will be activated Note that if the alarm disable switch is in the NORM position a print command will be sent to the console The alarm disable toggle switch in the upper right hand corner of the microprocessor circuit board quiets the audible alarm when placed in the up TEST position and prevents print commands from being
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