GSI-3100 CAP2

CAP2 “Capacitance Accurate Probe 2” provides Level, Interface (Optional), Multiple Spot RTD’s (up to 5), and Average Temperature from a single probe..

The CAP2 is a unique level gauge, it’s designed for both inventory and process applications. The CAP2 meets Custody transfer accuracy under API Chapter 3.1B (Second Edition), Standard Practice for Level Measurement of Liquid Hydrocarbons in Stationary Tanks by Automatic Tank Gauging (Manual of Petroleum Measurement Standards).

The CAP2 sensor has no moving parts, is rigid in construction, and easy to install in tanks upto 20’ in height. The CAP2 sensor is simply a combination of stainless steel pipes. Virtually no maintenance, i.e., no magnets, no floats, no delicate components, and no silicon inside the process.

Physically a transmitter card is located within the transmitter head in a NEMA 4x weatherproof or NEMA 7 Explosion proof enclosure on top of the gauge. An “Intrinsic Barrier” is necessary for Intrinsically Safe installations. One Intrinsic Barrier Set per four CAP2 gauges is required.

The CAP2 transmitter card features comprehensive self-calibration and self- diagnostic capabilities. The CAP2 is not affected by the change in the dielectric constant or temperature of the product in the tank.

Digital communication from the CAP2 is via IEEE RS 485 Electrical Standard using MODBUS RTU Protocol. Digital output is required in inventory or custody transfer applications, where the full accuracy resolution of the CAP2 is required.
For process control Two (2) 4-20ma outputs are (optionally) provided. The two analog outputs are configurable, the output is selectable from any of the data variables.

Digital communications to and from the CAP2 is MODBUS RTU Protocol. This is an industry standard. MODBUS RTU is compatible with most Distributed Control Systems (DCS), Programmable Logic Controllers (PLC’s), and/or Remote Terminal Units (RTU’s).

The “ISB” Intrisic Barrier Box, comes with a set of I.S. Barriers in either a NEMA 4x weatherproof or NEMA 7 Explosion proof enclosure. An optional line insulator / repeater is available within the ISB for communications over long wiring runs or for faster baud rates.

Optionally, GSI manufactures the E/TGI and E/IFI communication devices:

The GSI E/TGI can be configured with I.S. Barriers, line insulator, Interface convertor, Power conditioner and local display (ground reader) for up to Four (4) CAP2 gauges. The GSI E/TGI can be used as a local display, topology converter, protocol converter, data concentrator, or programmable device for specialized applications. The E/TGI is configurable with other forms of communications such as Fiber Ethernet, Radio, Cellular, Satellite, or WEB enabled.

The GSI E/IFI “Enhanced Intelligent Field Interface” can be configured with I.S. Barriers with each RS 485 / MODBUS RTU “IPM” Intelligent Personality Mobule. Each IPM can handle up to Four (4) CAP2 gauges. The E/IFI can support upto Thirty-two (32) IPM’s of the same type or different electrical standards and protocols. The GSI E/TGI can be used as a remote field interface, topology converter, protocol converter, data concentrator, or programmable device for specialized applications. The E/TGI is configurable with other forms of communications such as Fiber Ethernet, Radio, Cellular, Satellite, or WEB enabled. Thus, the E/IFI allows the integration of CAP2 gauges along with other sensor technologies into most systems on the market. Consult GSI on specific configurations.

CAP2 Applications

The CAP2 is designed to measure non-conductive liquids such as petroleum-based product and gases. Typical applications include LPG or LNG bullet tanks, Aboveground storage tanks (additive tanks, distribution tanks, fuel tanks, etc.), Below ground tanks (service stations, airport fueling tanks, etc.), Barges, Tank trucks, and Railroad tank cars.

CAP2 for use in any proper application currently using an existing capacitance probe with Analog output or wanting more accuracy with a Digital output.
  • CAP2 for use with LPG or LNG. Because of the extreme temperature and pressure ranges of bullet tanks, this gauge provides the best solution for LPG or LNG product applications.
  • CAP2 for use with clean products within underground or cylinder tanks, i.e., applications where Magnetostrictive gauges (magnets and floats) have proven to be a maintenance concern and TDR is not accurate enough for the application.
  • CAP2 for use within transportation vessels (Barges, Tank trucks, and Railroad tank cars). The CAP2 is a rugged device constructed out of stainless steel pipes. It uses low voltage and is an Intrinsically Safe device. E/TGI’s are used as stationary receivers at loading racks with I.S. electrical connection to the CAP2 once stationary.
  • CAP2 for use directly with Cellular Micro-burst, Satellite, or WEB enabled communications for remote Vendor Managed Inventory (Distribution or Pick-up).