Gems Sensors & Controls ELS-950, ELS-950M Operating Manual

Instruction Bulletin No. 225480

ELS-950 Series

Electro-Optic Level Switch

Specifications

Materials
Housing and Prism
Operating Pressure
Operating Temperature
Input Volt age
Output Configuration
Current Consumption
(No Load)
Repeatability
Ambient Light Immunity
Approval

Polysulfone
0 to 250 psig, (0 to 17 bar) Max.

-40°F to 230°F (-40°C to +110°C)

See Part Number Chart

Open drain may sink 40mA max.
~ 4mA @ 5Vdc
~ 10mA @ 12 Vdc
±1 mm
See Ambient Light Test
U.L. Pending

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Specifications

Note: Not for use in freezing liquids

Installation

1. For NPT threaded units:
a. Use Teflon (TFE) thread tape or Permatex #80725 plastic pipe sealant to seal thread. Caution: Pipe sealant must not come in

contact with prism surface.

b. Thread sensor into tank wall and tighten by hand. Further tighten an additional one to two threads past hand-tightness. (Avoid

2. For 1/2" and M12 straight threaded units:

3. Sensor may be installed in horizontal or up to 45° from horizontal plane for best operation. Vertical mounting is possible, may be droplet sensitive,

4. Caution: Do not install sensor close to infrared sources or incandescent light. Reflective surfaces may interfere with proper operation of the optical

5. Connect voltage supply (Vdc + 10%) Between red (+) and black (-) of the unit.

Caution: Do not connect output (blue wire) to Vdc power without a load.
See wiring diagrams for output configuration.

overtightening, as this may damage threads.)

a. Thread sensor into tank wall by hand until sensor housing contacts tank wall surface. ( See below for mating o-ring gland design

information.)

b. The sensor shall be torque tightened to 12 to 24 in-lb ( 1.4 to 2.7 N-m). This range is slightly more than “hand-tight” to insure sealing,

and less than that which would cause housing or thread damage.

c. CAUTION: Under no circumstances shall the sensor be tightened more than 1/6 turn beyond that required to seat the bottom of the

sensor housing with the outside wall of the tank.
depending on viscosity of media.
sensor. (Consult Gems Sensors if prism is to be mounted less than 2” from any reflective surface.)

Special caution should be taken to meet EN61000-4-5 Surge Immunity if any of the following conditions apply to the installation: The product
is installed outside; the cable is greater than 30 meters in length. In order to meet the Surge Immunity requirements, the following conditions
must be followed during installation:

1. Shielded cable must be used, and the shield must be tied to earth ground (not power supply ground) on at least one end of the cable
shield/drain wire. The shield must be maintained all the way from sensor to the power supply.

2. If unshielded cable is used, an earth grounded metal conduit can be used to replace the shielded cable.

3. For the sensor with metal body or enclosure the body/enclosure must be grounded to earth. If a protective metal housing is used, the
metal housing should be grounded to earth.

4. If a protective plastic housing is used, the housing must be able to withstand at least 2 kV from the housing to earth ground.

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Test

Sensors

Test Container(s)

Light Meter
GE Model #214

Ú

The test depicted below was performed to determine the sensor
immunity level to ambient light. The recorded ambient is the maximum
level at which the sensor performs/detects normally.

Variac

Black Container

390 FT-CD

Max Ambient Light

Opaque Container

30 FT-CD

Note: 1 Ft-Cd = 10.7 Lux
Above testing is based on minimum readings of

at least two (2) samples.

Typical Wiring Diagrams

External Load

Red

L
o

5 or

12 Vdc

+

-

Black

Blue

a
d

Sensor

1/2" Straight Thread

SAE #5 TUBE FITTING

Mating O-Ring Gland Design

12°

.555

(AT TOP)

∅

.550

.108
.093

Note: May sink up to 40mA max. Use diode
suppression for inductive loads.

CMOS / TTL Output

Red

R

Output

5 Vdc

+

-

Black

Blue

Sensor

Max. current sink = 40mA
R = Pull-up Resistor (4.7K 1/4W)

Relay Output

-

V

5 or

+

12 Vdc

+

-

*

Red

Sensor

Black

Blue

Note: * For inductive loads, use diode suppression

1/2-20 UNF 2B

M12 X 1 Straight Thread

45°

∅ .570 ± .002

[14.5 ± .05 mm]

.020
[.50 mm]

M12 X 1 - 8G

Return Policy

Returns are accepted on stock items up to 30 days from date
of order. You must contact our Returns Department for a
Return Authorization (RA) number. Return the goods - freight
prepaid - in the original container and include original packing
slip.
C. O. D. returns are not accepted. Gems reserves the right
to apply restocking charges.

Tel: [phone]
Fax: [phone]

.150
[3.80 mm]

Maintenance

Sensor may require a periodic cleaning of prism surface. Chlorinated hydrocarbons must not be used for cleaning.
A mild detergent may be used to clean prism surface.

Dimensions

11/16” NPT Mounting

1/4”
NPT

1 7/16”

(35.36 mm)

1 1/16” HEX

(17.5 mm)

M12 x 1

1 7/16”

(35.36 mm)

Electrical Termination: Lead Wires, 22 AWG, TPE Jacketed, 6” to 8” Extended

Important Points:

• Gems products must be maintained and installed in strict accordance with the National
Electrical Code and the applicable Gems Product Instruction Bulletin that covers
installation, operation and proper maintenance. Failure to observe this information may
result in serious injury or damages.

• Please adhere to the pressure and temperature limitations shown throughout this catalog
for our sensors. These limitations must not be exceeded. These pressures
and temperatures take into consideration possible system surge pressures, temperatures
and their frequencies.

• Selection of materials for compatibility with the media is critical to the life and operation of
Gems products. T ake care in the proper selection of materials of construction, testing is
required.

M12 x 1

O-Ring

11/16” HEX

(17.5 mm)

• Our sensors have been designed to resist shock and vibration. However, shock and
vibration should be minimized.

• Filter liquid media containing particulate and/or debris to ensure the proper operation of
our products.

• Electrical entries and mounting points in an enclosed tank may require liquid/vaporsealing.

• Our sensors must not be field-repaired.

• Physical damage sustained by product may render it unserviceable.

Gems Sensors Inc.

One Cowles Road
Plainville, CT 06062-1 198
Toll-Free: 1-800-378-1600

1/2” - 20 UNF

1/2”-20 UNF

O-Ring

1 7/16”

(35.36 mm)

11/16” HEX

(17.5 mm)