Series-PBLT2

Supported Applications

The Dwyer Series PBLT2 and PBLTX Submersible Level Transmitters are designed for measuring liquid level in harsh environments. The series is specifically suited for wastewater, slurry applications, oil tanks, chemical storage, and sludge pits where a durable cage design with a large-diameter 316 SS diaphragm seal prevents clogging from floating solids.

Operating Conditions & Performance

The transmitters utilize a piezoresistive sensing element to measure the height of liquid referenced to atmospheric pressure. Accuracy is specified as ±0.25% FS (includes linearity, hysteresis, and repeatability) for configured ranges at or above 5 psi; ranges below this threshold are noted with ±1% FS accuracy. The series supports measurement up to a maximum of 5000 psi or 1500 feet.

Performance is maintained across specific temperature envelopes depending on the model and cable type:

• PBLT2 Process Temperature: 0 to 200°F (-18 to 93°C)
• PBLTX with ETFE Cable: -4 to 176°F (-20 to 80°C)
• PBLTX with Polyurethane Cable: -4 to 149°F (-20 to 65°C)

The response time is documented as 50 msec. The pressure limit for the series is rated at 2X FS.

Ventilation and Protection Features

• Atmospheric Compensation: A ventilation tube within the shielded, vented cable automatically compensates for changes in atmospheric pressure above the tank. The vent includes a filter to block dust, dirt, and water droplets.
• Surge Protection (PBLT2): Features dual arrestor technology grounded to the case to eliminate power supply surges and lightning ground strike transients. Note: Surge protection is not guaranteed and is not covered by warranty.
• Cable Strength: Equipped with a 270-pound tensile strength cable.

Configuration Options

The series offers configurable options for measurement range, cable length, and hazardous location compliance. The model number guide follows the format: PBLT2 - - - .

Measurement Ranges & Cable Lengths

• Ranges: Available in psi (up to 5000 psi maximum) and feet (up to 1500 feet maximum). Specific standard ranges include 5, 10, 15, 20 psi and metric equivalents such as 3.5M, 5M, 10M.
• Cable Lengths: Configured lengths are available from 10 to 2000 ft (3 to 610 m). Standard options include 40, 60, 70, 80, and 100 feet.

Cable Types & Materials

• ETFE: Default cable type (indicated by blank in ordering).
• Polyurethane (-PU): Available as an option code.
• Wetted Materials: Body: 316 SS, 316L SS; Cable: Polyether polyurethane or ETFE; Seals: Fluoroelastomer.

Hazardous Location Approvals (PBLTX)

The PBLTX variant is intrinsically safe and carries the following certifications:

• cULus Intrinsically Safe: Class I, Div. 1, Groups A, B, C, D; Class II, Div. 1, Groups E, F, G; Class III, Div. 1.
• ATEX: EU Type Certificate NO. DEMKO 18 ATEX 2080 (II 1 G Ex ia IIC T4 Ga and II 1 D Ex ia IIIC T135C Da).
• IECEx & UKCA Ex: Certified under EN/IEC 60079-0 and 60079-11 standards.

The PBLT2 model holds CE and UKCA approvals but does not include intrinsic safety certification in the standard configuration. Use of associated apparatus for hazardous locations requires adherence to Control Drawing 001833-44 or 001833-47.

Power & Output

• PBLT2 Power: 13-30 VDC; Loop Resistance: 900 Ω at 30 VDC (datasheet) or 850 Ω at 30 VDC (manual).
• PBLTX Power: 10-28 VDC.
• Output Signal: 4-20 mA DC, two wire for both models.

Key Product Differences

The Series PBLT2 and PBLTX differ primarily in their electrical protection features and hazardous location certifications. The PBLT2 includes built-in lightning and surge protection utilizing dual arrestor technology, whereas the PBLTX is designed for intrinsically safe applications with specific entity parameters (Ui ≤ 28VDC, Ii ≤ 93mA) but lacks the dedicated surge protection circuitry of the standard model.

Temperature limits also vary by cable construction. The ETFE-equipped units support a higher ambient temperature range (-4 to 176°F / -20 to 80°C) compared to Polyurethane-equipped units (-4 to 149°F / -20 to 65°C). Additionally, the PBLTX is not field repairable and must be returned for service if needed.

Accessories available include a Dessicant filter (A-297) for vent tube humidity protection, a 316 SS cable hanger (A-625), an intrinsically safe galvanic isolator (MTL5041), and an intrinsically safe zener barrier (MTL7706).