The 121 wirewound precision resistor series from Riedon offers resistance values between 700kΩ up to 3.8MΩ (lower resistances available upon request) at a power rating of 0.5W, tolerances as low as ±0.005% and a standard TCR of ±10 ppm/°C (wide TCR range, including Balco & Platinum wire for high TCR, available upon request). These resistors use a traditional design for through-hole circuit board mounting, while offering a number of custom features. The 121 series resistors are all 100% acceptance tested and tracable to NIST, and offer long term stability of 100ppm/year (20 ppm/year version available). Matched resistance sets to ±0.001% and ±0.5 ppm/°C are also available.

• Wirewound, precision, axial through-hole resistor
• Available in resistance values between 700kΩ and 3.8MΩ (lower resistances available upon request)
• Minimum tolerance ±0.005%
• Standard TCR of ±10 ppm/°C (wide TCR range of -20 ppm/°C to +6000 ppm/°C available upon request)
• Standard long term stability of 100 ppm/year, with high stability version (±20 ppm/year) available upon request
• Fast rise time version with low reactance design for fast rise time and extended frequency response available upon request
• 100% acceptance tested / traceable to NIST
• Power rating of 0.5W
• Maximum working voltage 400V
• Matched resistance sets to ±0.001% and ±0.5ppm/°C available
• Temperature range -55°C to +145°C

Please see below for the power derating curve for the Riedon 100/SM/PC series:

The below table gives the full specifications for each resistor model available in the Riedon 100/SM/PC wirewound resistor range, including the 121 series: