GR precision wirewound resistors provide a higher resistance stability and a higher initial calibration accuracy than any other class or resistor. They also offer excellent noise levels and lower temperature coefficients.
Description
Innovators and manufacturers of ultra-precision wirewound resistors and test instruments used as laboratory standards and for critical process monitoring.
General Resistance ultra-precision resistors have been used for over 50 years in precision measurement instruments by manufacturers around the world.
GR precision wirewound resistors should be specified whenever precision circuit operation is to be maintained over a prolonged period of time.
These resistors provide a higher resistance stability and a higher initial calibration accuracy than any other class of resistor. They also offer excellent noise levels and lower temperature coefficients.
The highest quality materials are used in the manufacture of these essential circuit elements. General Resistance design engineers customarily employ high quality copper alloys such as Evanohm, Karma, Moleculoy, Stabilohm, Zeranin and equivalent in order to achieve higher predictability and flatter temperature responses. And all critical manufacturing stages are conducted in environmentally controlled "clean rooms."
Standard resistance range: any value from 1 ohm to 1.1 Megohms.
Standard accuracies: +/-0.1%, +/-0.025%, and +/-0.01%.
Standard tempco: +/-5ppm/°C max (-55°C to +125°C)
Special order: virtually any accuracy, tempco, resistance value or ratio matching required by your specific application.
GR maintains substantial quantities of standard accuracies as listed:
213.0µO/0.1 in. (84µO/mm) 134.5µO/0.1 in. (53µO/mm) 84.6µO/0.1 in. (33.3µO/mm)
Noise
Immeasurable
Mechanical
Resistance Wire
Highest quality copper alloy drawn from melts of known resistivity and controlled Temco
Winding
Balanced muliple p for low reactance
Protection
Hand-applied RTV silicone coating
Outer casing
Molded shell sealed with epoxy
Marking
Permanent ink, direct reading
Leads
Axial, tinned copper
Specifications: GR compared to Mil Specs
MIL-R-93 Limit
MIL-R-39005 Limit
GR (typ.)
Minimum insulation resistances: Dry/Wet (?R)
>109O/108O
>109O/108O
>1010O/109O
Temperature Cycling (?R)
±(.2% +50mO)
±(.05% +10mO)
±(.001% +5mO)
Short-term overload (?R)
±(.1% +50mO)
±(.01% +10mO)
±(.003% +5mO)
Moisture resistance (?R)
±(.1% +50mO)
±(.1% +10mO)
±(.001% +3mO)
Dielectric withstanding voltage @ atm. pres. (VRMS)
500
750
1000
Load life, full rated power @ 70°C (?R)
±(.5% +50mO)
--
±(.0035% +5mO)
High temp. exposure @ 150°C (?R)
±(.1% +50mO)
±(.1% +10mO)
±(.001% +5mO)
Low temp. operation (?R)
±(.25% +50mO)
±(.1% +10mO)
±(.001% +3mO)
Resistance to soldering heat (?R)
N/A
±(.01% +10mO)
±(.001% +3mO)
Shock & vibration (high frequency) (?R)
±(.1% +50mO)
±(.01% +10mO)
±(.001% +3mO)
Listing of all applicable MIL Specifications:
MIL-R-93: Precision Wirewound Resistors
MIL-R-39005: High Reliability Wirewound Resistors
MIL-STD-883, Method 2003: Solderability
MIL-STD-202, Method 208: Solderability
MIL-STD-202, Method 210A, Cond. C: Resistance to Soldering Heat
MIL-STD-202, Method 215: Marking Resistance to Solvents
MIL-STD-202, Method 106D: Moisture Resistance
MIL-STD-202, Method 102A, Cond. C: Temperature Cycling
MIL-STD-202, Method 301 Dielectric Withstanding
MIL-STD-202, Method 302 Cond. A or B: Insulation Resistance
MIL-STD-202, Method 205D, Cond. C: Shock
MIL-STD-202, Method 204B, Cond. D: Vibration
MIL-STD-202, Method 211A, Cond. A and D: Terminal Strength
Power Derating Curve:All GR Precision Wirewound ResistorsPower dissipation at ambient temperature: GR resistors are designed to operate at full load up to +85°C. At temperatures in excess of +85°C derating curves must be observed. If power ratings are exceeded, the resistor may not perform at specified accuracy.
