268XA
Service Manual
1-26
FAI A/D Thermocouple per ITS-1990 Measurement Specifications
The following tables provide FAI A/D specifications for the thermocouple measurement
function per ITS-1990.
Table 1-33. FAI A/D Thermocouple General Specifications
Specification
Characteristic
Input Impedance
100 M
Ω
minimum in parallel with 300 pF
Open Thermocouple Detect
Operates by injecting a small ac signal into the input after each
measurement. A thermocouple resistance greater than 1 k
Ω
to 10 k
Ω
is detected as an open input.
Temperature Coefficient
To calculate Thermocouple accuracy for temperatures between 28
°
C and 60
°
C, or -10
°
C and 18
°
C, use a linear interpolation
between the two applicable points. For example, if the applicable
specification at 28
°
C is 0.6 and the specification at 60
°
C is 1.1, then
the specification at 40
°
C is =(1.1-0.6)x(40-28)/(60-28)+0.6=0.7875.
Accuracy at -20
°
C
Multiply the -10
°
C to +60
°
C accuracy specification by 2. After 1
hour warm-up. For accuracy between -10
°
C and -20
°
C, interpolate
linearly.
Table 1-34. FAI A/D Thermocouple Specifications
Ac
°
C
Thermocouple
Resolution
18
°
C to 28
°
C
-10
°
C to 60
°
C
ITS90
°
C
90 Day
1 Year
1 Year
Type
Temperature
°
C
Slow
Slow
Fast
Slow
Fast
B
600 to 1200
2
3.60
3.90
8.50
4.00
8.60
1200 to 1550
2
2.10
2.40
5.00
2.60
5.20
1550 to 1820
1
2.00
2.30
4.70
2.70
5.00
C
0 to 150
2
1.90
2.00
4.00
2.10
4.20
150 to 650
1
1.60
1.70
3.50
1.80
3.60
650 to 1000
.5
1.40
1.70
3.20
2.00
3.50
1000 to 1800
.5
2.00
2.50
4.50
3.20
5.30
1800 to 2316
.5
3.10
3.80
6.80
5.10
8.10
E
-100 to -25
.3
0.80
0.90
1.50
1.00
1.60
-25 to 20
.2
0.70
0.70
1.20
0.80
1.30
20 to 600
.2
0.60
0.70
1.10
0.80
1.20
600 to 1000
.2
0.60
0.80
1.20
1.10
1.50
Summary of Contents for 2680A
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Page 204: ...268XA Service Manual 7 10 268X FINAL ASSEMBLY alg105f eps Figure 7 1 268XA Final Assembly ...
Page 207: ...Replaceable Parts Parts Lists 7 7 13 2680A DIO alg100f eps Figure 7 3 DIO Module ...
Page 209: ...Replaceable Parts Parts Lists 7 7 15 2680A FAI alg102f eps Figure 7 4 FAI Module ...
Page 211: ...Replaceable Parts Parts Lists 7 7 17 2680A PAI alg103f eps Figure 7 5 PAI Module ...
Page 214: ...268XA Service Manual 8 2 ...
Page 215: ...8 3 8 Schematic Diagrams Figure 8 1 Backplane PCA 2680A 4001 ...
Page 216: ...268XA Service Manual 8 4 Figure 8 1 Backplane PCA cont 2680A 1001 ...
Page 217: ...8 5 8 Schematic Diagrams Figure 8 2 Controller System Power PCA 2680A 4004 ...
Page 223: ...8 11 8 Schematic Diagrams Figure 8 3 Digital I O PCA 2680A 4006 ...
Page 224: ...268XA Service Manual 8 12 Figure 8 3 Digital I O PCA cont 2680A 1006 1 of 3 ...
Page 225: ...8 13 8 Schematic Diagrams Figure 8 3 Digital I O PCA cont 2680A 1006 2 of 3 ...
Page 226: ...268XA Service Manual 8 14 Figure 8 3 Digital I O PCA cont 2680A 1006 3 of 3 ...
Page 227: ...8 15 8 Schematic Diagrams Figure 8 4 Backplane Extender PCA 2680A 4009 ...
Page 228: ...268XA Service Manual 8 16 Figure 8 4 Backplane Extender PCA cont 2680A 1009 ...
Page 229: ...8 17 8 Schematic Diagrams Figure 8 5 Extender PCA 2680A 4010 ...
Page 230: ...268XA Service Manual 8 18 Figure 8 5 Extender PCA cont 2680A 3010 ...
Page 231: ...8 19 8 Schematic Diagrams Figure 8 6 A D Supply Assembly 2680A 4031 ...
Page 232: ...268XA Service Manual 8 20 Figure 8 6 A D Supply Assembly cont 2680 1031 ...
Page 233: ...8 21 8 Schematic Diagrams Figure 8 7 PCMCIA PCA 2680A 4041 ...
Page 234: ...268XA Service Manual 8 22 Figure 8 7 PCMCIA PCA cont 2686 1041 ...
Page 235: ...8 23 8 Schematic Diagrams Figure 8 8 Output PCA 2680A 4062 ...
Page 236: ...268XA Service Manual 8 24 Figure 8 8 Output PCA cont 2680A 1062 ...
Page 237: ...8 25 8 Schematic Diagrams Figure 8 9 A D PFE PCA 2640A 4003 ...
Page 238: ...268XA Service Manual 8 26 Figure 8 9 A D PFE PCA cont 1 of 6 ...
Page 239: ...8 27 8 Schematic Diagrams Figure 8 9 A D PFE PCA cont 2 of 6 ...
Page 240: ...268XA Service Manual 8 28 Figure 8 9 A D PFE PCA cont 2640A 1003 3 of 6 ...
Page 241: ...8 29 8 Schematic Diagrams Figure 8 9 A D PFE PCA cont 2640A 1003 4 of 6 ...
Page 242: ...268XA Service Manual 8 30 Figure 8 9 A D PFE PCA cont 2640A 1003 5 of 6 ...
Page 243: ...8 31 8 Schematic Diagrams Figure 8 9 A D PFE PCA cont 2640A 1003 6 of 6 ...
Page 244: ...268XA Service Manual 8 32 Figure 8 10 A D FFE PCA 2645A 4003 ...
Page 245: ...8 33 8 Schematic Diagrams Figure 8 10 A D FFE PCA cont 2645A 1003 1 of 6 ...
Page 246: ...268XA Service Manual 8 34 Figure 8 10 A D FFE PCA cont 2645A 1003 2 of 6 ...
Page 247: ...8 35 8 Schematic Diagrams Figure 8 10 A D FFE PCA cont 2645A 1003 3 of 6 ...
Page 248: ...268XA Service Manual 8 36 Figure 8 10 A D FFE PCA cont 2645A 1003 4 of 6 ...
Page 249: ...8 37 8 Schematic Diagrams Figure 8 10 A D FFE PCA cont 2645A 1003 5 of 6 ...
Page 250: ...268XA Service Manual 8 38 Figure 8 10 A D FFE PCA cont 700p29_topress zip 2645A 1003 6 of 6 ...
Page 251: ...8 39 8 Schematic Diagrams Figure 8 11 Analog Input Connector PCA 2620A 4004A ...
Page 252: ...268XA Service Manual 8 40 2620A 1004 Figure 8 11 Analog Input Connector PCA cont ...
Page 253: ...8 41 8 Schematic Diagrams Figure 8 12 Display PCA 1 of 1 ...
Page 254: ...268XA Service Manual 8 42 Figure 8 12 Display PCA cont 1 of 1 ...