Tank Level Type Gauges

0-10” H2O to 0-800” H2O

  • Safe working Pressures up to 1000 PSI
  • Rugged construction Weather Proof design
  • Common Applications:
    • Pressurized Tank Level Monitoring
    • Stationary Tanks – Horizontal or Vertical
    • Tanker Transport
  • For materials such as LOX, CO2, Ammonia, Nitrogen, Helium, Nitrogen Hydrogen and Argon
  • Gauge, Switch and Transmitter Options

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Model 114 Tank Level Diaphragm Type Gauge Description:

Mid-West® Instrument Diaphragm ΔP Gauges – ± 2% Full Scale Accuracy. With the Diaphragm type tank level gauge the high and low-pressure ports are completely isolated from each other. There is no bypass and therefore they can be used for air, gas and liquids. They also come in a variety of dial scales allowing for very sensitive measurements. The Differential Pressure is sensed by the movement of an elastomer diaphragm against a precision calibrated range spring. The change in position of the diaphragm in response to the change in Differential Pressure moves an internal magnet. This magnet, in turn, causes a rotary magnet external to the gauge body to rotate, track the movement of the diaphragm and the attached pointer indicates ΔP on a dial.

Diaphragm-Type Tank Level Gauges are available with one or two hermetically sealed reed switches. The switches are adjustable within a defined percentage of the full scale range of the gauge and are available in SPDT and SPST, normally open configurations for various load/power ratings. The switches can be pre-set to activate or deactivate on falling or rising tank level pressure. Switches are “CE” marked per the EU Low Voltage and RoHS Directive.

Mid-West Instrument 114 Tank Level transmitter is a 2 wire loop powered microprocessor based 4-20 mA transmitter. The magnetic angle sensor & electronics senses the angle (relative to the transmitter sensor) of the magnet which moves linearly in the bore. Each transmitter is individually calibrated to the gauge using an 11 point calibration linearization technique. Transmitter options can  be  CE marked for compliance to the EMC Directive upon request .

Model 114


Models 115 & 116 Tank Level Bellows Type Gauge Description:

Mid-West® Instrument Bellows ΔP Gauges – ± 1% Full Scale Accuracy. System pressure is applied to the internal volume of a bellows and mechanical linkage assembly.  As pressure changes, the bellows and linkage assembly move to cause  an  electrical  signal to  be  produced  or  to  cause  a  gauge pointer to move. The major components of the Model’s 115 and 116 are a two-piece body, bellows sensing element and over-pressure assembly, a torque tube assembly, a range spring and the gauge front assembly.

The body halves provide the pressure containment function. They also clamp the sensing element and over-pressure assembly between the halves, isolating the high side and low side pressures of the system. The high side body half also provides a mount for the torque tube assembly and the gauge front assembly.

The sensing element is exposed to the differential pressure and deflects in response to the differential pressure. This assembly incorporates a bidirectional relief valve which provides over-pressure protection in both directions. When over-pressured from the high side, the valve is opened by a mechanical stop as the sensing element deflects to its maximum travel. When over-pressured from the low side, the spring-loaded valve opens when the differential pressure exceeds its maximum rating. The opening of the valve in either direction equalizes the pressure and protects the unit. A range spring is provided to adjust the spring rate of the system to suit the various differential pressure ranges of the instrument.

Model 115

Model 116


OEM, Private Label, Special Dials

Mid-West Instrument has the capability to design and engineer a Differential Pressure Gauge, Switch or Transmitter to the exact requirements of the customer. Dial size, Process connection Size and location, etc. can also be customized to the customer’s requirements. Mid-West has one of  the fastest production times in the Industry. Our standard production time on most gauges is 7-10 business days or less.

Mid-West Instrument has the equipment and printing technology to provide color dials, flow scales and customer logo dials.

Please contact your Sales Coordinator for additional information and terms.

Tank Level , Diaphragm Type

Model No. Differential Pressure Range Accuracy Working Pressure Electrical Available Specifications Installation/ Operation Manual Electrical IOM Drawing
Model 114 0-0.72 PSID (0-20" H20) to 0-20 PSID (0-600" H2O)
Tank Level Applications
±2% 1000 PSI CE / LVD, RoHS Compliant, NEMA 4X, 4-20mA Transmitter

Tank Level , Bellows Type

Model No. Differential Pressure Range Accuracy Working Pressure Electrical Available Specifications Installation/ Operation Manual Electrical IOM Drawing
Model 115 0-10" H2O to 0-69.9" H2O
Tank Level Applications
±1% 500 PSI (Optional 1,000 PSI) None available N/A
Model 116 0-70" H2O to 0-800" H2O
Tank Level Applications
±1% 500 PSI (Optional 1,000 PSI) MICRO SWITCHES
0-80" H2O to 0-800" H2O NEMA 4X, CSA LISTED IND. CONT. EQUIP.
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