PCM-2 Manual.pdf - Voss Associates

particles incorrectly counted as alphas, however the opposite error (counting
alphas as betas) will increase rapidly.
Before changing these thresholds, it is strongly recommended that representative
calibration sources be used. Ideally, samples of the actual isotopes to be detected
should be used to measure the changes in response to both contamination sources
and background. If thresholds are changed, detector efficiencies should also be
re-checked.
Modular Detector Board Parts List
The following table lists the electronic items incorporated in the Modular Detector
Board and should contain any part necessary for normal repair. Unless otherwise
specified, callouts of manufacturers or manufacturers' part numbers are to be
considered typical examples only and not restrictions against using equivalent
parts with the same operating characteristics. When ordering parts from Eberline,
specify model number, serial number, reference designator, value, Eberline part
number, or a word description if the part has no reference designation. Eberline
will automatically substitute equivalent parts when one called out by the
manufacturers' part number is not available.
Modular Detector Board, YP11543000
Ref. Desig. Part Name Part Description Manufacturer and
Part Number
Eberline Part
Number
(None) Circuit Board Modular Detector Eberline Instruments ZPl1543002
Al Microprocessor 83C51 Mask ROM Eberline Instruments Consult Factory
A2 I.C. Quad NOR gate (Any) 74HC02 ICHCAOOO02
A3 I.e. +5 V Regulator (Any) 7805 TO­
0220
ICAV7805
A4 I.C. +5 V Regulator National LP2950CZ ICAVA2950C
A5 I.C. RS-485 Xcvr. Linear Tech LT485 ICCMA485
A7 Hybrid Custom Hybrid EIC VEBDl4
XAI I.e. Socket 40-Pin DIP (Any) SOIC140
XA2 I.C. Socket 14-Pin DIP (Any) SOICl14
XA5 I.C. Socket 08-Pin DIP (Any) SOIC308
CI,5-7 Capacitor 10 liF, 16V Tant. Spr.
199DI06XOOICAI
CPTAIOOM4X
C2,C3 Capacitor 33 pF, Ceramic Erie CKl2BX330K CPCE330P3P
13-4
PCM2.MAN/ Rev A/April 1995