RI-21 Series Dry Reed Switch
RI-21 Series
Micro dry-reed switch hermetically sealed in a gas-filled envelope.
Single-pole, single-throw (SPST) type, having normally open contacts,
and containing two magnetically actuated reeds.
The switch is of the double-ended type and may be actuated by an
electromagnet, a permanent magnet or a combination of both.
The device is intended for use in sensors, relays, pulse counters or
similar devices.
RI-21 Series Features
General purpose reed switch
High breakdown voltage
Contact layers: gold, plated ruthenium
Superior glass-to-metal seal and blade alignment
Excellent life expectancy and reliability
Dimensions in inches (mm)
General data for all models RI-21
AT-Customization / Preformed Leads
Besides the standard models, customized products can
also be supplied offering the following options:
!
Operate and release ranges to customer
specification
!
Cropped and/or preformed leads
Coils
All characteristics are measured using the Philips
Standard Coil. For definitions of the Philips Standard
Coil, refer to “Application
Notes”
in the
Reed Switch
Technical & Application Information
Section of this
catalog.
Life expectancy and reliability
The life expectancy data given below are valid for a
coil energized at 1.25 times the published maximum
operate value for each type in the RI-21 series.
No load conditions (operating frequency: 100Hz)
Life expectancy : min. 10
8
operations with a failure
rate of less than 10
-9
with a confidence level of 90%.
110
End of life criteria:
Contact resistance > 1Ω after 2 ms
Release time > 2 ms (latching or contact sticking).
Loaded conditions (resistive load: 12 V; 4 mA;
(15 mA peak); operating frequency: 170 Hz)
Life expectancy: min. 10
7
operations with a failure rate
of less than 10
-8
with a confidence level of 90%.
End of life criteria:
Contact resistance > 2Ω after 4 ms
Release time > 0.7 ms (latching or contact
sticking). Switching different loads involves
different life expectancy and reliability data. Further
information is available on request.
Mechanical Data
Contact arrangement is normally open; lead finish is
tinned; net mass is approximately 190 mg; and can be
mounted in any position.
COTO TECHNOLOGY (USA)
Tel:
(401) 943-2686 / Fax (401) 942-0920
6
(Europe) Tel: +31-45-5439343 / Fax +31-45-5427216
RI-21 Series Dry Reed Switch
Shock
The switches are tested in accordance with “IEC 68-2-
27”, test Ea (peak acceleration 150 G, half sinewave;
duration 11 ms). Such a shock will not cause an open
switch (no magnetic field present) to close, nor a switch
kept closed by an 80 AT coil to open.
Vibration
The switches are tested in accordance with “IEC 68-2-
6”, test Fc (acceleration 10G; below cross-over fre-
quency 57 to 62 Hz; amplitude 0.75 mm;
frequency range 10 to 2000 Hz, duration 90 minutes).
Such a vibration will not cause an open switch (no
magnetic field present) to close, nor a switch kept
closed by an 80 AT coil to open.
Mechanical Strength
The robustness of the terminations is tested in accor-
dance with “IEC 68-2-21”, test Ua
1
(load 40 N).
Operating and Storage Temperature
Operating ambient temperature; min: -55°C;
max: +125°C. Storage temperature; min: -55°C; max:
+125°C.
Note:
Temperature excursions up to 150°C
may be permissible. For more information contact your
nearest Coto Technology sales office.
Soldering
The switch can withstand soldering heat in accordance
with “IEC 68-2-20”, test Tb, method 1B: solder bath at
350 ±10°C for 3.5 ±0.5 s. Solderability is tested in
accordance with “IEC 68-2-20”, test Ta, method 3:
solder globule temperature 235°C; ageing 1b: 4 hours
steam.
Welding
The leads can be welded.
Mounting
The leads should not be bent closer than 1 mm to the
glass-to-metal seals. Stress on the seals should be
avoided. Care must be taken to prevent stray magnetic
fields from influencing the operating and measuring
conditions.
6
For Most Recent Data, Consult the Coto Technology Website:
www.cotorelay.com
E-mail: sales@cotorelay.com
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