Barksdale BLS3000 Electronic Dual Level Switch with Display

A continuous level switch in a compact stem for hydraulic and lube tanks

The Barksdale BLS3000 is an electronic level switch built on a stainless steel 316Ti stem with a reed-switch sensor and a foam NBR float. It reports level with a 5 mm (1/5 inch) resolution on a 4-digit red LED display, offers one or two PNP switch points and an optional 4-20 mA or 0-10 V analog output, and it uses a redundant measurement system so the reading stays reliable. Settings are made with three push-buttons and the display and M12 connector rotate by 320 degrees.

Barksdale lists level control for hydraulics, lubrication systems and cooling. Output can be shown in distance units (percent, mm, cm, m, inch, feet) or volume units (litres, cubic metres, gallons), so the display can read the tank content directly once the tank geometry is entered.

Technical specifications

Stem lengths, connections and ordering code

The total length L0 is 9.8 inch (250 mm), 14.6 inch (370 mm) or 16.1 inch (410 mm) as standard, with other lengths on request up to 39.4 inch (1000 mm). Process connections shown on the drawing are G1/2, G3/4, G1, M20 x 1.5, 1/2, 3/4, 1 and 1 1/4 inch NPT, and 7/8-14 (SAE 10) and 1 1/16-12 (SAE 12) O-ring boss threads. Because each thread leaves a top and bottom dead band (about 27 mm for G1/2 and M20 threads and about 13 mm for the NPT threads, with tolerances printed on the datasheet), the usable measuring length LM is L0 minus both dead bands; size the stem against the minimum and maximum levels you need to monitor. The datasheet example code is BLS3 1 6 X M 14.6Z. Seals are FKM, EPDM or NBR; the plug is M12 x 1 with 4, 5 or 8 pins depending on the output selection.

Float, accuracy and electrical data

The BN17 float is 0.70 inch in diameter and 0.98 inch high (17.8 x 25 mm) and needs a medium density of at least 0.02 lb per cubic inch (0.60 g per cubic centimetre); it sits about 15 mm deep in water and 19 mm in oil of density 0.75. Accuracy is plus or minus 1 digit without turbulence, including temperature influence and repeatability, and maximum pressure is 43.5 psi (3 bar). Supply is 15 to 28 V DC, reverse-polarity protected, about 50 mA without load (80 mA on output code 6). The current output allows a load of RI = (Ub – 12 V) / 20 mA, which is 600 ohm at 24 V; the switch outputs handle 500 mA, short-circuit proof, up to 100 Hz, with a delay of 0.0 to 50 s and a 0 to 125 percent adjustment range.

Installation and what to confirm before ordering

Medium temperature is -13 to 176 F (-25 to 80 C), ambient -4 to 158 F (-20 to 70 C) and storage -22 to 176 F; the enclosure is Type 1 / Type 4X (IP65) / Type 6 (IP67). The enclosure is 1.6 inch diameter by 4.5 inch for a 1/2 inch NPT thread, and weight is about 0.77 lb for a G1/2 thread with a 250 mm stem. cULus approval applies with a maximum ambient of 140 F and supply of 28 V DC. Confirm the tank liquid density, the pressure against the 3 bar limit, the stem length and dead bands, the thread, the seal compatibility and the output code. The attached file is the two-page datasheet (bulletin L0043-C); other level products are in level instrumentation. Send the full code and quantity for a quotation.

How the Barksdale BLS3000 works

A float rides up and down the stem with the liquid level. Reed switches inside the stem sense the float position. The electronics turn the position into a level reading, switch outputs and an optional analog signal.

Where the BLS3000 is used

• Hydraulic tanks
• Lubrication systems
• Cooling systems
• Oil reservoirs
• Machine tool tanks

Selection checklist for the BLS3000

• Stem length
• Process connection
• Switch point count
• Analog output
• Seal material
• Medium density
• Medium temperature
• Connector pin count

Installation, commissioning and maintenance notes for the BLS3000

Fit the stem into the tank through the process connection and plug in the M12 cable. Enter the tank data and set the switch points with the push-buttons. Check the float movement at regular intervals.

Requesting a quotation for the Barksdale BLS3000

Please send the stem length, the process connection and the outputs needed. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

BLS3000 device type

It is an electronic dual level switch with a display.

BLS3000 maker

It is made by Barksdale.

BLS3000 stem

The stem is 316Ti stainless steel.

BLS3000 sensor

It uses a reed-switch sensor.

BLS3000 float

The float is made of foam NBR.

BLS3000 redundancy

A redundant measurement system keeps the reading reliable.

BLS3000 resolution

The level resolution is 5 mm.

BLS3000 display

A 4-digit red LED display shows the level.

BLS3000 display units

Units include percent, mm, cm, m, inch, feet, litres, cubic metres and gallons.

BLS3000 tank content

The display can read tank content directly once the tank geometry is entered.

BLS3000 switch outputs

It has one or two PNP switch points.

BLS3000 switch modes

Each switch point can be set to normally open, normally closed or window mode.

BLS3000 switch delay

The switch delay can be set from 0.0 to 50 s.

BLS3000 analog output

An optional 4-20 mA or 0-10 V output is available.

BLS3000 settings

Three push-buttons set the parameters.

BLS3000 rotation

The display and the M12 connector rotate by 320 degrees.

BLS3000 supply

The supply is 15 to 28 V DC.

BLS3000 stem lengths

Standard lengths are 250, 370 and 410 mm, with others up to 1000 mm.

BLS3000 seals

Seals are FKM, EPDM or NBR.

BLS3000 pressure

Maximum pressure is 3 bar.

BLS3000 medium temperature

Medium temperature runs from minus 25 to plus 80 degrees C.

BLS3000 float density

The medium density must be at least 0.60 g/cm3.

BLS3000 connector

The electrical connection is an M12 plug.

BLS3000 weight

It weighs about 350 g in the 250 mm version.

Switch records for the BLS3000

Record the switch points, the tank data and the date of each check.

Choosing the right BLS3000 stem length

Choose the stem length from the tank height and the levels to watch.