Hydraulic Lifts in Longwall Mining Equipment Using ULS-200 Solid-State Level Sensors

Hydraulic lift systems are used to raise and lower an arm on a shearer (also called a power loader) to cut coal from the coalface. Reliable hydraulic oil level sensing is required to maintain continuous operation efficiently and safely.


Challenge: Hydraulic oil coating the prism on optical sensors causes inconsistent sensing of critical fluid level creating concerns over reliability. The sensor is unable to accurately detect fluid levels.


Optical type sensors used in these applications are subject to coating build-up and other reliability concerns due to the LED refraction technology used. Coating present on the prism can prevent repeatable detection of hydraulic oil level, limiting the sensor’s accuracy.

Gems Sensors’ ULS-200 Advanced Level Sensor

uls-200 level sensor

Uniquely designed to reduce customer downtime, the rugged and compact ULS-200 with microcontroller has no moving parts and reliably senses oil, water, and harsh chemicals. In addition to meeting IP67, Gems ULS-200 meets IP6K9K – a more stringent requirement for high-pressure/high-temperature washdowns. This high-rated IP standard reduces customer worry about moisture ingress in tough outdoor environments. Gems’ ULS-200 comes pretested to industry-leading temperature (-40°F to 257°F/-40°C to 125°C), vibration (to 2000 Hz per IEC 60068-2-64), and pressure (up to 300 PSIG/20.7 bar) standards to reduce your overall product testing.

Features & Benefits: 

  • No moving parts
  • Durable sealed design – IP6k9k 
  • Ease of use – simple installation
  • Wide temperature range
  • Excellent in harsh environments