3500 Series/Low Thermal EMF Reed Relays

The 3500 Series is ideally suited to the needs of Instrumentation, Data Acquisition and Process Control. The specification tables allow you to select the appropriate relay for your particular application. Recommended for use in high accuracy DVM’s, Multiplexers and Digital or Analog Multipoint Recorders. If your requirements differ from the selection options, please consult Coto’s Factory to discuss a custom reed relay.

3500 Series Features

  • Low Thermal EMF: < 10 µV through < 0.5 µV with 50 nV stability
  • Patented Low Thermal Design. U.S. Patent #4,084,142
  • Low power coils to ensure low thermal EMF
  • High Insulation Resistance - 1012Ω
  • Control/Signal isolation of 1500 VDC
  • High reliability, hermetically sealed contacts
  • Form A, Dry or Hg Wetted contacts. High Dielectric Strength
  • Epoxy coated steel shell provides magnetic shielding
  • RoHS compliant (except for 3520)

3500 SERIES DIMENSION

In Inches (Millimeters)
  • 3500 mechanicals
  • 3500 mechanicals
  • 3500 mechanicals
  • 3500 mechanicals

3500 SERIES TECHNICAL INFORMATION

Top View4:
Dot stamped on top of relay refers to pin #1 location
Grid = .1”x.1” (2.54mm x 2.54mm)

  • 3500 schematic
  • 3500 schematic
  • 3500 schematic
  • 3500 schematic
  • 3500 schematic

1Consult factory for life expectancy at other switching loads.
2Models 3501 and 3540, optional electrostatic shield is tied to pin #5. Models 3502, 3520 and 3541, optional electrostatic shield is tied to pin #13.
3Model 3520 has Hg wetted contacts - position sensitive, must be mounted within 30° of vertical plane. See schematic. Hg content per capsule: Form A, 0.04 grams.

Storage Temp: -35°C to +100°C; Operating Temp: -20°C to +85°C; Solder Temp: 270°C max; 10 sec. max
All electrical parameters measured at 25°C unless otherwise specified.
Vibration: 20 G’s to 2000 Hz; Shock: 50 G’s