Gas Tank Lid Monitoring Sensor - Digi-Key

Gas Tank Lid Monitoring Sensor
REED RELAYS REED SENSORS REED SWITCHES
Introduction
In and around the gas tank and its filling lid is consider a highly explosive area.
Anything that can possible cause a spark could potentially ignite the fuel. Use of
an electromechanical sensor to detect if the lid and fuel cap are in place could
potential cause a spark across the sensor contacts. Detecting if the lid and gas
cap are in place designers have turned to the Reed Sensor which uses
hermetically sealed reed switches, and are further packaged in a tough plastic
encapsulation.
Figure 1. MK14 Sensor physical layout
Features
• The reed switch used in the Reed Sensor is
hermetically sealed and is therefore not sensitive
and therefore any sparks across the contacted
are hermetically sealed from the environment
• EX approved and intrinsically safe available
• The hermetically sealed reed switch is ideally
suited for switching low signal level voltages and
currents which do not draw an arc
Figure 2. Gas tank lid with magnet is closed activating reed switch contacts to remain
closed.
• Magnet and Reed Sensor are isolated and
have no physical contact by typically having the
magnet mounted to the lid and the Reed Sensor
mounted on the gas cap
• The magnet is not affected by its environment
• Millions of reliable operations
• Cylindrical hole and screw fastening mounting
• Contacts dynamically tested
• Large sensing distances possible
Applications
• Ideal for sensing gas lid closure and gas cap
in place.
• Ideal for applications sensing closure of an
assortment of different lids and/or caps
Figure 3. When gas tank lid is opened the magnet moves away from the reed swtich
sensor causing the contacts to open which activated an alarm.
Reed Sensors are Ideal for Sensing Gas Lid and Gas Cap are
in Place
The immediate area in and around the gas cap can be defined as having a
potential explosive atmosphere. Any potential arc or spark could ignite the
gasoline. Gas lids and gas caps can easily be forgotten to have closed either
by the vehicle operator or by a service attendant. Furthermore, with gasoline
prices continuing to rise, gasoline theft directly from the tank is on the rise.
MEDER electronic
Application
MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected]
MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected]
Page 1 of 2
www.meder.com
Gas Tank Lid Monitoring Sensor
REED RELAYS REED SENSORS REED SWITCHES
Specifications
Operate specs
Min Max Units
Must close distance
5
25
mm
Must open distance
5
25
mm
Hysteresis
Load Characteristics
Switching voltage
Switching current
Carry current
Contact rating
Static Contact
resistance
Dynamic contact
resistance
Breakdown voltage
voltage
Operate time
Release time
Operate Temp
Storage Temp
Typical 50%
Min Max Units
200
0.5
1.5
10
150
200
320
0.5
0.1
-20 85
-20 85
V
Amps
Amps
Watts
mΩ
mΩ
V
msec
msec
°C
°C
To solve the above three problems, designer are now going to Reed Sensors.
The sensor indeed serves three purposes: 1 It eliminates the potential of an arc
or spark across its contacts making it to the outside world by using hermetically
sealed reed switches. In this case, any arc or spark occurring across the
contacts is enclosed in the hermetically sealed atmosphere of the reed switch,
eliminating itself as a potential ignition device. 2. Generally, a magnet is
mounted on the gas lid and the reed sensor is mounted on the gas cap. If both
are not in place a signal is sent to the on-board computer locking the ignition
system not allowing the vehicle to be turned on. 3. If the car is in the locked
position and an attempt is made to remove the gas lid, this also triggers the onboard computer, which sounds an alarm.
MEDER’s line of EX approved intrinsically reed sensors are ideal for this
application. Electromechanical switches are not hermetically sealed and
therefore any arc or spark generated across its contacts could represent a
potential ignition point.
MEDER’s reed sensors are available in several packages with various
connector or lead options allowing the users to meet exact design details.
Because of the multitude of design requirements, MEDER has the capability of
developing specialized packaging for both the reed sensor and the magnet to
meet the user’s specific needs.
Consider some of the below option standard options as well.
Cylindrical Panel Mount Series
Series
MK03
MK03
Dimensions
mm
Dia
5.25
L
25.5
Illustration
inches
0.207
1.004
MK14
MK14
Dia
L
4
25.5
0.157
1.004
MK18
MK18
Dia
L
5
17
0.197
0.669
MK20/1
MK20/1
Dia
L
2.72
10
0.107
0.394
Rectangular Screw Flange Mount Series
Series
MK04
MK05
MK05
Dimensions
mm
W
13.9
H
5.9
L
23.0
W
19.6
H
6.1
L
23.2
Illustration
inches
0.547
0.232
0.906
0.772
0.240
0.913
W
14.9
0.587
H
6.9
0.272
L
32.0
1.260
**Consult
the factory for more options not listed above.
**
MK12
MK12
MEDER electronic
Application
MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected]
MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected]
Page 2 of 2
www.meder.com