Small Size – Engineered Plastics
LS-3 Series – Offers High Reliability, Compact Sizeand Low Costs in NPT, Straight and Metric Threads
Ideal for shallow tanks or restricted spaces, or for any low-cost, high volume use.
LS-3 Series are available in FDA compliant materials, consult GEMS for details.

LEVEL SWITCHES – SINGLE POINT

Polysulfone Float

Polypropylene Float(Hollow)

Polypropylene Float(Solid)

For water based liquids, with limited
use in oils and chemicals.

Features a low specific gravity float
offering broad chemical compatibility.

With Polypropylene stem andfloat, switch offers broad chemicalcompatibility.

Buna N Float

ALL-PVDF

New 3/4˝ Polypropylene
Float

FDA

FDA
Wetted materials ofconstruction comply with
FDA food contact regulations.

Ideal for oils and fuels.

Stem and float of corrosion-resistant
PVDF for ultra-pure applications.

See next page for details.

Common Specifications

Approvals: U .L. Recognized – File No. E45168; CSA Listed – File No. 30200. CE Declaration Available Upon Request.
NSF materials are NSF 169 Standard compliant. For NSF approved level switches contact Gems.
Switch SPST: 20 VA, 120-240 VAC. Units are shipped N.O. unless otherwise specified. Selectable, N.O. or N.C., by inverting float on unit stem.

Dimensions – 1˝ Float Models only

Alternate Mountings
3/8˝-16
Straight Thread

1/8˝ NPT
17/32˝(13.4 mm)

2-3/32˝(53.2 mm)

1/2˝ HEX

L1✝

1-9/16˝(39.7 mm)

M12x 1.75
Straight Thread

3/8˝ – 16

L1= Actuation Level(see chart below) 1/2˝ HEX.390˝ REF.
(9.9mm).14˝(2.6mm)

1˝(25.4 mm)

1˝ DIA(25.4 mm)

A-1†G1/8˝
1/8˝-28 BSP

Electrical
Termination

1/2˝
HEX

Lead Wires

Visit www.GemsSensors.com for most current information.

.475˝ REF.
(12mm).315˝ REF.
(8.0mm)9/16˝HEX.14˝(3.6mm)

Cable

5/8˝
HEX.20˝(5.1mm)Cable

BU24_C_LS-3_20140417

FLOAT TYPE
Stem andMounting Material

Float
Material

Float
Dia.

Polysulfone

Polysulfone

1˝

Polypropylene2

Polypropylene(Hollow)

Polypropylene3
Polypropylene3
NSF Std. 169(Hollow)(Kynar float retaining
NSF Std. 169
clip)

Polypropylene2

Polypropylene(Solid)Nylon

PVDFMin. Liquid
Sp. Gravity.75

Pressure Max.
@ 70°F (21°C)
50 psi(3 bar)OperatingTemperature-40°F to +225°F(-40°C to +107°C)

Mounting
TypeElectricalTermination

Part Number

1/8˝ NPT

Lead Wires

42295-40°F to +225°F(-40°C to +107°C)

1/8˝ NPT
3/8˝-16
G 1/8˝-28
M12x1.75
1/8˝ NPT
3/8˝-16

Lead Wires
Lead Wires
CableCable
Lead Wires
Lead Wires

142505171517171518189739209475

G 1/8˝-28
M12x1.75
1/8˝ NPT
3/8˝-16

Lead Wires
Lead Wires
Lead Wires
Lead Wires

209455209460209465116826171514-40°F to +176°F(-40°C to +80°C)

M12x1.75

Cable

189787-40°F to +212°F(-40°C to +100°C)

1/8˝ NPT

Lead Wires

201540-40°F to +250°F (oil)(-40°C to +121°C [oil])

1/8˝ NPT

Lead Wires

162745-40°F to +176°F (water)(-40°C to +80°C [water])

M12x1.75

Cable

1897861˝

13/16˝(20.6 mm).60

50 psi(3 bar)1˝

13/16˝(20.6 mm).60

50 psi(3 bar)1˝

9/16˝(14.3 mm).90

150 psi(10 bar) @68°F (20°C)

3/4˝

7/16˝(11.1 mm).95

Atmospheric

1˝

13/16˝(20.6 mm).45

150 psi(10 bar)

3/4˝

11/16˝(17.5mm).85

150 psi(10.3 bar)

-40°F to +250°F (oil)(-40°C to +121°C [oil])

1/8˝ NPT

Lead Wire

1778181˝

1/2˝(12.7 mm).86

50 psi(3 bar)-40°F to +250°F(-40°C to +121°C)

1/8˝ NPT

Teflon Jacketed
Lead Wires

173250

Buna

PVDF

Actuation
Level1
3/4˝(19.0 mm)-40°F to +176°F(-40°C to +80°C)-40°F to +225°F(-40°C to +107°C)-40°F to +150°F(-40°C to +66°C)

LEVEL SWITCHES – SINGLE POINT

How To Order – Select Part Number based on specifications required.

– Stock Items.

Notes:
1. Based on a liquid specific gravity of 1.0.
2. All Polypropylene units carry a Kynar retaining clip. Accessories Available in OEM Quantities: Jam Nut, Gaskets, and Slosh Shields.
3. NSF 169 Approved unit, for water use only.

3/4˝ Diameter Floats for Tiny Tanks
Our smallest LS-3 yet!
 Reliable alternative to more expensive electronic sensors.
 Fits smaller devices. Less material, lower cost.
 Proprietary float more buoyant than competitors.
Small yes, but with BIG performance. No other 3/4˝ float switch on themarket matches our LS-3 specs. These units are ideal for potable water,
medical devices and other compact appliances, such as printers. Gems
proprietary float enables use in lighter-than-water fluids. NSF/ FDA compliant
models available at your request. Please consult factory.
Specifications
Wetted Material
Stem and Mounting		P/N 201540		P/N 177818
Float		P/N 201540		P/N 177818
Magnet		P/N 201540
Operating Temperature, Max.
P/N 201540
P/N 177818
Pressure, Max.
P/N 201540
P/N 177818
BU24_C_LS-3_20140417

Actual Size

Dimensions
17/32˝(13.4 mm)

Polypropylene with Kynar retaining clip
Nylon
Polypropylene
Buna-N

1/8˝ NPT
1/2˝ HEX

L1†
2-3/32˝(53.2 mm)
1-9/16˝(39.7 mm)

1˝(25.4 mm)†

3/4˝ DIA(19 mm)

Ceramic
212°F (100°C)
250°F (121°C) oil, -40°F to +176°F (-40°C to +80°C)
Atmospheric
150 psi (10.3 bar)

L1= Actuation Level(see chart above)

Order by Part Numbers:
LS-3, 3/4˝ Polypropylene Float: 201540
LS-3, 3/4˝ Buna–N Float: 177818

Visit www.GemsSensors.com for most current information.

A-2

Unique Features Make These LS-3 Models Special
These small switches feature uniqueconfigurations for special applications.
Part No. 142545
With Slosh Shield

LEVEL SWITCHES – SINGLE POINT

Part No. 46999
Bottle Level

Part No. 76707
For Low Level

For external mounting ontanks too small to accommodate internally mountedswitches. (See notebelow)

For detecting levels as low
as 5/8˝ from tank bottom.
Use in water, some oils andchemicals.

Cut-away version shown

Compact, all-polypropylene
switch with slosh shield isideal for use with turbulent
liquids in small tanks. FDA
compliant materials.

3/8˝-24NPSM
THD.
3/8˝-24
NPSM
THD.

1/8˝1/8˝NPTNPT
17/32˝
17/32˝(13.4mm)(13.4mm)

1/8˝1/8˝
NPTNPT(3.2(3.2mm)mm)

25/64˝
25/64˝(10(10mm)mm)

STEM

1/2˝1/2˝
HEXHEX(12.7mm)(12.7mm)

FLOAT
3-15/32˝
3-15/32˝(88.1mm)(88.1mm)

9/16˝
9/16˝
2-3/32˝
2-3/32˝ (14.3 mm)† †(14.3 mm)(53.2mm)(53.2mm)

1-13/16˝
1-13/16˝
2.09˝
2.09˝ACTUATION† †(46.1 mm)
L1=3/4”mm)(53.1mm)
LEVEL (46.1 mm) (53.13 1/2” REF.

1/2˝1/2˝
HEXHEX(13(13mm)mm)
1-15/32˝
1-15/32˝(37.3mm)(37.3mm)15/16˝
15/16˝
(23.8mm)(23.8mm)1-9/16˝
1-9/16˝(39.7mm)(39.7mm)

1/4˝1/4˝
NPTNPT
1-1/4˝
DIA.DIA.
1-1/4˝(31.7mm)(31.7mm)

Order By Part Number

1/8”-27 NPSM TH’D1-1/4˝
1-1/4˝(31.7mm)(31.7mm)1/4” NPT REF.
(2) PLACES

1 9/16”
DIA. REF.
1-9/16˝
DIA.DIA.
1-9/16˝(39.6mm)(39.6mm)#22 AWG WIRE,POLYMERIC
72”-78”EXT.
1/4˝1/4˝
NPTNPT

0.250˝
0.250˝
(6.4(6.4mm)mm)

1.86˝
DIA.DIA.
1.86˝(47.4mm)(47.4mm)

142545

46999

76707

All Polypropylene (Including Shield4)

Polysulfone

All Polysulfone (Including Collar)

Polypropylene (Solid)

Polysulfone

Buna N

Other Wetted—Brass, Aluminum, Polycarbonate, Viton A

Epoxy

Min. Liquid Sp. Gr.

.90.75—-40°F to +150°F (-40°C to +65.6°C)-40°F to +120°F (-40°C to +48.9°C)

Materials
Stem and Mounting
Float

Operating Temperature
Pressure, PSI, Max.

3

Switch1, SPSTElectrical Termination

150Notes:
1. See “Electrical Data” on Page X-5 for more information.
2. Switch operation is selectable, N.O. or N.C., by inverting the float on the unit stem.
3. Maximum pressure at 70°F (21°C).
4. Consult factory for other available materials.
† L1= Switch actuation level, nominal (based on a specific gravity of 1.0).

A-3

20 VA, N.C. Dry

20 VA, N.C./N.O. Dry2
No. 22 AWG, 22˝ L., PVC Lead Wires-40°F to +180°F (-40°C to +82.2°C)
50

No. 22 AWG, 72˝ L., Polymeric Lead Wires

No. 22 AWG, 72˝ L., PVC Lead Wires

Note: LS-3 Series Bottle Level Switch is also available with any of the float materials shown on opposite
page. Contact GEMS for correct part number.
– Stock Items.

Visit www.GemsSensors.com for most current information.

BU24_C_LS-3_20140417