Appendix C.Model 4420HT – High Temperature Version
Model 4420HT is a high-temperature crackmeter, rated to 200 °C. This model is supplied with 316 stainless steel U-joints on the ends, as opposed to the rod end bearings installed on standard crackmeters. Due to the U-joint configuration, the overall instrument assembly length is 35 mm (1.375") longer, which you must add when determining anchor spacing distance using in Table 1.
The epoxied diameter is slightly larger with the HT version due to added waterproofing and strain relief for the Teflon cable. This results in a space of about 14.5 mm (0.569") between the U-joint and the outer diameter of the epoxy. The standard spacer supplied with anchors as shown in Figure 5 and Figure 6 is about 12.7 mm (.500"); therefore, interference between the epoxied area and the mounted surface may occur. To ensure this doesn’t happen, either rotate the assembly 180 degrees on its axis, or use the larger supplied spacers.
4420HT crackmeters are supplied with a high temperature thermistor that has a range of -55 to +300 °C, and an accuracy of ±0.5 °C. To convert ohms to temperature, use Equation 7 or Table 8 below.
Thermistor Type: US Sensor 103JL1A
Resistance to Temperature Equation:
|
T = |
1 |
– 273.15 |
|
A+B(LnR)+C(LnR)3+D(LnR)5 |
equation 7: Model 4420HT 10KΩ Thermistor Resistance
Where:
T = Temperature in °C
LnR = Natural Log of Thermistor Resistance
A = 1.127670 x 10-3
B = 2.344442 x 10-4
C = 8.476921 x 10-8
D = 1.175122 x 10-11
Note: Coefficients optimized for a curve J Thermistor over the temperature range of 0 °C to +250 °C.
|
Temp |
|
|
32,650 |
0 |
|
31,029 |
1 |
|
29,498 |
2 |
|
28,052 |
3 |
|
26,685 |
4 |
|
25,392 |
5 |
|
24,170 |
6 |
|
23,013 |
7 |
|
21,918 |
8 |
|
20,882 |
9 |
|
19,901 |
10 |
|
18,971 |
11 |
|
18,090 |
12 |
|
17,255 |
13 |
|
16,463 |
14 |
|
15,712 |
15 |
|
14,999 |
16 |
|
14,323 |
17 |
|
13,681 |
18 |
|
13,072 |
19 |
|
12,493 |
20 |
|
11,942 |
21 |
|
11,419 |
22 |
|
10,922 |
23 |
|
10,450 |
24 |
|
10,000 |
25 |
|
9,572 |
26 |
|
9,165 |
27 |
|
8,777 |
28 |
|
8,408 |
29 |
|
8,057 |
30 |
|
7,722 |
31 |
|
7,402 |
32 |
|
7,098 |
33 |
|
6,808 |
34 |
|
6,531 |
35 |
|
6,267 |
36 |
|
6,015 |
37 |
|
5,775 |
38 |
|
5,545 |
39 |
|
5,326 |
40 |
|
5,117 |
41 |
|
4,917 |
42 |
|
4,725 |
43 |
|
4,543 |
44 |
|
4,368 |
45 |
|
4,201 |
46 |
|
4,041 |
47 |
|
3,888 |
48 |
|
3,742 |
49 |
|
3,602 |
50 |
|
3,468 |
51 |
|
3,340 |
52 |
|
3,217 |
53 |
|
3,099 |
54 |
|
2,986 |
55 |
|
2,878 |
56 |
|
2,774 |
57 |
|
2,675 |
58 |
|
2,579 |
59 |
|
2,488 |
60 |
|
2,400 |
61 |
|
2,316 |
62 |
|
2,235 |
63 |
|
2,157 |
64 |
|
2,083 |
65 |
|
2,011 |
66 |
|
1,942 |
67 |
|
1,876 |
68 |
|
1,813 |
69 |
|
1,752 |
70 |
|
1,693 |
71 |
|
1,637 |
72 |
|
1,582 |
73 |
|
1,530 |
74 |
|
1,480 |
75 |
|
1,432 |
76 |
|
1,385 |
77 |
|
1,340 |
78 |
|
1,297 |
79 |
|
1,255 |
80 |
|
1,215 |
81 |
|
1,177 |
82 |
|
1,140 |
83 |
|
1,104 |
84 |
|
1,070 |
85 |
|
1,037 |
86 |
|
1,005 |
87 |
|
973.8 |
88 |
|
944.1 |
89 |
|
915.5 |
90 |
|
887.8 |
91 |
|
861.2 |
92 |
|
835.4 |
93 |
|
810.6 |
94 |
|
786.6 |
95 |
|
763.5 |
96 |
|
741.2 |
97 |
|
719.6 |
98 |
|
698.7 |
99 |
|
678.6 |
100 |
|
659.1 |
101 |
|
640.3 |
102 |
|
622.2 |
103 |
|
604.6 |
104 |
|
587.6 |
105 |
|
571.2 |
106 |
|
555.3 |
107 |
|
539.9 |
108 |
|
525.0 |
109 |
|
510.6 |
110 |
|
496.7 |
111 |
|
483.2 |
112 |
|
470.1 |
113 |
|
457.5 |
114 |
|
445.3 |
115 |
|
433.4 |
116 |
|
421.9 |
117 |
|
410.8 |
118 |
|
400.0 |
119 |
|
389.6 |
120 |
|
379.4 |
121 |
|
369.6 |
122 |
|
360.1 |
123 |
|
350.9 |
124 |
|
341.9 |
125 |
|
333.2 |
126 |
|
324.8 |
127 |
|
316.6 |
128 |
|
308.7 |
129 |
|
301.0 |
130 |
|
293.5 |
131 |
|
286.3 |
132 |
|
279.2 |
133 |
|
272.4 |
134 |
|
265.8 |
135 |
|
259.3 |
136 |
|
253.1 |
137 |
|
247.0 |
138 |
|
241.1 |
139 |
|
235.3 |
140 |
|
229.7 |
141 |
|
224.3 |
142 |
|
219.0 |
143 |
|
213.9 |
144 |
|
208.9 |
145 |
|
204.1 |
146 |
|
199.4 |
147 |
|
194.8 |
148 |
|
190.3 |
149 |
|
186.1 |
150 |
|
181.9 |
151 |
|
177.7 |
152 |
|
173.7 |
153 |
|
169.8 |
154 |
|
166.0 |
155 |
|
162.3 |
156 |
|
158.6 |
157 |
|
155.1 |
158 |
|
151.7 |
159 |
|
148.4 |
160 |
|
145.1 |
161 |
|
142.0 |
162 |
|
138.9 |
163 |
|
135.9 |
164 |
|
133.0 |
165 |
|
130.1 |
166 |
|
127.3 |
167 |
|
124.6 |
168 |
|
122.0 |
169 |
|
119.4 |
170 |
|
116.9 |
171 |
|
114.5 |
172 |
|
112.1 |
173 |
|
109.8 |
174 |
|
107.5 |
175 |
|
105.3 |
176 |
|
103.2 |
177 |
|
101.1 |
178 |
|
99.0 |
179 |
|
97.0 |
180 |
|
95.1 |
181 |
|
93.2 |
182 |
|
91.3 |
183 |
|
89.5 |
184 |
|
87.7 |
185 |
|
86.0 |
186 |
|
84.3 |
187 |
|
82.7 |
188 |
|
81.1 |
189 |
|
79.5 |
190 |
|
78.0 |
191 |
|
76.5 |
192 |
|
75.0 |
193 |
|
73.6 |
194 |
|
72.2 |
195 |
|
70.8 |
196 |
|
69.5 |
197 |
|
68.2 |
198 |
|
66.9 |
199 |
|
65.7 |
200 |
|
64.4 |
201 |
|
63.3 |
202 |
|
62.1 |
203 |
|
61.0 |
204 |
|
59.9 |
205 |
|
58.8 |
206 |
|
57.7 |
207 |
|
56.7 |
208 |
|
55.7 |
209 |
|
54.7 |
210 |
|
53.7 |
211 |
|
52.7 |
212 |
|
51.8 |
213 |
|
50.9 |
214 |
|
50.0 |
215 |
|
49.1 |
216 |
|
48.3 |
217 |
|
47.4 |
218 |
|
46.6 |
219 |
|
45.8 |
220 |
|
45.0 |
221 |
|
44.3 |
222 |
|
43.5 |
223 |
|
42.8 |
224 |
|
42.1 |
225 |
|
41.4 |
226 |
|
40.7 |
227 |
|
40.0 |
228 |
|
39.3 |
229 |
|
38.7 |
230 |
|
38.0 |
231 |
|
37.4 |
232 |
|
36.8 |
233 |
|
36.2 |
234 |
|
35.6 |
235 |
|
35.1 |
236 |
|
34.5 |
237 |
|
33.9 |
238 |
|
33.4 |
239 |
|
32.9 |
240 |
|
32.3 |
241 |
|
31.8 |
242 |
|
31.3 |
243 |
|
30.8 |
244 |
|
30.4 |
245 |
|
29.9 |
246 |
|
29.4 |
247 |
|
29.0 |
248 |
|
28.5 |
249 |
|
28.1 |
250 |