specification 513 series ceramic trimmer capacitors capacitance: when measured at room temperature (25 c 5c) and at a frequency of 0.1 to 1 megahertz, the minimum capacitance shall not be greater than that specified at minimum setting with a +10% tolerance, and the maximum capacitance shall not be less than that specified at maximum setting with a -10% tolerance. "q" factor: when measured at room temperature (25 c 5c), at a frequency of approximately 1 mega- hertz, the capacitor at approximately maximum rated capacitance setting shall have a "q" value not less than indicated for the respective style. insulation resistance: the insulation resistance at approximately maximum capacitance setting shall be 10 gigaohms minimum at room temper- ature of (25 c 5c) when measured at 100 volts dc in a series with a protec- tive resistance not exceeding 1 mega- ohm after no more than one minute application of the voltage. dielectric strength: the capacitor, set at approximately maxi- mum capacitance shall withstand volt- age between terminals for 1 to 5 sec. as indicated for the respective style. (50ma maximum charging current) torque: when measured at room temperature (25 c 5c), the torque required to start and maintain rotation of the rotor through one full turn, shall be as indicated for the respective style. temperature characteristic: the temperature characteristic of capacitance shall be within the limits shown in the following table. the temperature characteristic shall be determined by measuring the capaci- tance (capacitor shall be set at approx- imately 75% of the guaranteed maxi- mum capacitance) +25c, -55c, and either +85c or +125c, which- ever is applicable to the respective style, at a frequency of 0.1 to 1 megahertz. each measurement shall be made after the capacitor has reached thermal stability. capacitance drift: with the capacitor set at approximately 75% of the guaranteed maximum capaci- tance, the capacitance drift shall be determined as the greatest difference between any two of three 25c mea- surements, when temperature cycled as follows: +25c, -55c, +85c or +125c, whichever is applicable to respective style, +25c. the capaci- tance drift shall not exceed 0.75% or 0.5 r f, whichever is greater. accelerated life test: the capacitor, at approximately 75% of the guaranteed maximum capaci- tance, shall be tested for 250 hours at twice rated voltage, and at a tempera- ture equal to the maximum operating temperature 3c for the respective style. at the end of this period the capacitance shall not have changed more than 5% of its value before the life test or 0.5 r f, whichever is great- er; the insulation resistance shall be 1 gigaohm minimum and the "q" at 1 megahertz shall be at least 40% of the initial test limit. temperature cycling & humidity: the capacitor, at approx- imately 75% of the guaranteed maxi- mum capacitance, shall be given a treatment consisting of 5 temperature cycles as follows: cool capacitor to -55c 3c. remove the capaci- tor from the cooling chamber and allow it to reach room temperature. then place in an oven at a temperature equal to maximum operating tempera- ture 3c of the respective style. remove from oven and allow capaci- tor to cool to room temperature. the capacitor shall be held at the specified minimum and maximum temperatures long enough to reach equilibrium, and in no case less than 15 minutes. the rate of change of temperature in cool- ing from room temperature, or heating above it, shall not be less than 3c per minute. the temperature cycles shall be followed by exposure for 96 hours to a relative humidity of 95% at 40c 3c. the capacitor shall then be removed from the humidity cham- ber and held at 25c 5c with a maximum humidity of 50% for four hours. the insulation resistance shall be at least 1 gigaohm, the "q" at 1 mhz is at least 40% of initial test limit and the capacitance shall not have changed by more than 3% or 0.5 r f, whichever is greater, from its value prior to the start of the temperature cycling. dielectic type code percent capacitance change from value @ 25c -55c +85c min. max. min. max. a g -2.1 0.0 +4.2 +14.0 -3.8 -8.0 +1.1 -3.0
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