Lenz T-LLG-5 Industrial Fluid Level Gauge - Dual Level and Temp

In this review the Lenz T-LLG-5 fluid level gauge is evaluated for workshop and industrial tank monitoring. The bottom line: this compact 6.1 in sight glass combines clear fluid-level visibility with an integrated thermometer, making it a practical choice for maintenance technicians and equipment managers who need simultaneous level and temperature readings. The unit's polyamide construction, Buna-N O-ring seals and zinc-plated mounting hardware give confidence for commercial use, while the dual F/C thermometer and 1/2-13 threaded connection simplify installation and daily checks.

Key Features

• Dual measurement: The integrated thermometer displays temperature in both F and C alongside the sight glass so users can monitor level and temperature at once without extra gauges.
• High visibility: A transparent polyamide sight window provides a wide, clear view of liquid level for quick visual confirmation during routine inspections.
• Chemical resistance: Ultrasonically welded polyamide construction and Buna-N O-rings resist common industrial fluids, preserving clarity in harsh environments.
• Standard installation: Includes zinc-plated mounting bolts and a 1/2-13 threaded connection with 5 in bolt spacing for secure, leak-proof attachment to standard tanks.
• Universal fluid compatibility: Specified compatible with hydraulic oil, mineral oil, petroleum-based and water-based fluids for broad shop and plant use.
• Temperature rating: The thermometer is rated to 212F (100C), covering typical operating ranges for lubricants and hydraulic fluids.

Who It's For

The T-LLG-5 is suited for maintenance crews, hydraulic technicians and plant engineers who need a durable, low-maintenance sight gauge with temperature feedback built in. Its robust materials and standard threaded mounting make it a straightforward retrofit on industrial tanks and hydraulic reservoirs.

Those who require electronic temperature logging, digital readouts or non-contact level sensing should look elsewhere, since this model is a mechanical sight glass with a built-in analog thermometer and is designed for visual checks rather than automated monitoring.

Pros & Cons

Pros

• Clear, wide sight glass for easy level checks from multiple angles.
• Built-in F/C thermometer rated to 212F provides immediate temperature context without extra instruments.
• Durable construction with ultrasonic welds, Buna-N seals and zinc-plated hardware for longevity in industrial settings.
• Fits common 1/2-13 threaded openings and 5 in bolt spacing for straightforward installation.

Cons

• No electronic output or digital temperature logging, so it is not suitable for automated monitoring systems.

Specifications

Overall length	5.9 in (approx)
Sight glass length	6.1 in window measurement
Thread	1/2-13 threaded connection
Bolt spacing	5 in
Temperature range	Up to 212F (100C)
Construction materials	Transparent polyamide, Buna-N O-ring, zinc-plated bolts
Fluid compatibility	Hydraulic oil, mineral oil, petroleum and water-based fluids

Our Verdict

The Lenz T-LLG-5 is a practical, value-oriented sight gauge for industrial and hydraulic applications where visual level and manual temperature checks suffice. Its durable polyamide construction and standard hardware make it an easy upgrade for maintenance teams who need reliable, on-tank feedback without the complexity of electronic sensors.

Frequently Asked Questions

Can this gauge be used with hydraulic oil?
Yes, it is specifically compatible with hydraulic, mineral and petroleum-based oils as well as water-based fluids.

What temperature range does the built-in thermometer cover?
The onboard thermometer displays both F and C and is rated to 212F (100C).

How is the gauge mounted?
It uses a 1/2-13 threaded connection and 5 in bolt hole spacing with supplied zinc-plated bolts and Buna-N seals for a leak-proof mount.