ECA IS-34

Abstract

This industry standard covers the general requirements for cermet or metal film type resistor networks, primarily intended for incorporation into electronic circuits. <br>Classification <br>Networks specified herein (see 3.1) shall be identified by a part number which shall consist of the basic style and a dash number. Each article sheet covers a different network style. The dash number shall be coded to provide information concerning the network characteristic, resistance value, resistance tolerance and schematic. <br>Style <br>The style is identified by the three-letter symbol "RZS" followed by a three-digit Number. <br>Characteristic <br>The resistive Characteristic is identified by the single letter H, K or M. <br>Resistance <br>Equal Resistors - When all resistance values in the network are identical, the nominal resistance expressed in ohms is identified by four digits. Standard values are shown in Table II. The first three digits represent significant figures and the last digit specifies the number of zeros to follow. When the value of resistance is less than 100 ohm, or when the fractional values of an ohm are required, the letter "R" should be substituted for one of the significant digits to represent the decimal pint. When the letter "R" is used, succeeding digits of the group represent significant figures. The resistance value designations are shown in Tables II and III. Minimum and maximum resistance values for each style shall be as specified (see 3.1). <br>Unequal Resistors - When the resistance value within the network varies, then four digits should be used with the first digit being an "A," and the following three digits a code number indicating a resistance combination described in the applicable detail article sheet.