scope:

This specification covers the general requirements for general purpose insulated thermal resistors to be used for temperature compensation, control, and measurement over the temperature range specified (see 3.1).

The PIN shall be in the following form and as specified (see 3.1 and 6.1).

The style is identified by the symbol RTH followed by a two digit number. The letters identifies general purpose thermal resistors and the number identifies the physical configuration.

The characteristic is identified by a one-letter symbol in accordance with table I. TABLE I. Resistance ratio characteristic.

Symbol Resistance ratio characteristic ------------------------------------- A 19.8 ±10 percent B 29.4 ±10 percent C 48.7 ±10 percent D 0.5 ±10 percent E 0.55 ±10 percent

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Defense Electronics Supply Center, ATTN: DESC-ELDM, 1507 Wilmington Pike, Dayton, OH 45444-5765 by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

Resistor lead types are identified as solderable (type S) or weldable (type W), (see 3.3.1).

The direct current (dc) zero-power resistance measured at 25°C and expressed in ohms is identified by a three-digit number. The first two digits represent significant figures, and the last digit specifies the number of zeros to follow. The standard resistance values for every decade shall follow the sequence demonstrated for the "10 to 100", decade in table II. Resistance values not listed shall be considered as not conforming to the specification.

Examples: 101 = 100 ohms 102 = 1,000 ohms 103 = 10,000 ohms 105 = 1 megohm

TABLE II. Standard resistance values for the 10 to 100 decade.

5.0 10.0 20.0 5.0 10.0 20.0 -------------------------------------- 10.0 10.0 10.0 33.0 33.0 33.0 11.0 .... .... 36.0 .... .... 12.0 12.0 .... 39.0 39.0 .... 13.0 .... .... 43.0 .... .... 15.0 15.0 15.0 47.0 47.0 47.0 16.0 .... .... 51.0 .... .... 18.0 18.0 .... 56.0 56.0 .... 20.0 .... .... 62.0 .... .... 22.0 22.0 22.0 68.0 68.0 68.0 24.0 .... .... 75.0 .... .... 27.0 27.0 .... 82.0 82.0 .... 30.0 .... .... 91.0 .... ....

The zero-power resistance tolerance is identified by a single letter in accordance with table III. TABLE III. Resistance tolerance versus temperature for each resistance tolerance.

Sequence Temperature F G J K ± percent ± percent ± percent ± percent ----------------------------------------------------------------------------------- 1 −55 1/ 10 (15) 1/ 12 (17) 1/ 15 (20) 1/ 20 (25) 2 −15 1/ 5 (9) 1/ 6 (10) 1/ 9 (13) 1/ 14 (18) 3 0 3 4 7 12 4 25 1 2 5 10 5 50 3 4 7 12 6 75 5 6 9 14 7 100 7 9 12 17 8 125 10 12 15 20 9 2/ 200 15 18 25 30 10 2/ 275 20 25 35 40 1/ The percentages in parentheses are for positive temperature coefficient thermistors. 2/ These temperatures not applicable to all styles (see 3.1).