Celebrating 27 Years 1999-2026
Mid-West Diaphragm type gauges have ± 2% or ± 5% Full Scale Accuracy. The high and low-pressure ports are completely isolated from each other.
Accuracy, Build and Working Principle of Mid-West Diaphragm Gauges
There is no bypass and therefore they are ideally suited for use on dissimilar fluids, air, gases, or liquids with a high concentration of solids, etc. They also come in a variety of sizes 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. This rotary magnet has a pointer attached which indicates the differential pressure on the
dial.
Switch Configurations of Mid-West Diaphragm Gauges
Diaphragm-Type Differential Pressure Gauges are available with one or two hermetically sealed reed switches or 4-20mA transmitter depending on model. 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 or normally closed configurations for various load/power ratings. The switches can be set to activate or deactivate on rising or falling pressure. Switches are “CE” marked per the EU low voltage directive. Mid-West Diaphragm-type Differential Pressure Gauges can be configured for use in hazardous locations. All Hazardous Location Switches are both CSA and UL listed. The CSA & UL listings are for the entire assembly and not just the enclosure. IECEx certified switches are available now on model 240.
Mid-West Model 114 Diaphragm Type Tank Level Gauge
- Accuracy: ±2% Full Scale Descending Accuracy as per ASME B40.100 standards.
- Durable Construction: Glass-reinforced thermoplastic dial case, panel mountable with optional anodized aluminum case.
- Weather & Corrosion Resistant: NEMA 4X/IP66 protection ensures performance in harsh conditions.
- Shatter-Resistant Lens: Built for durability and safety.
- Over-Range Protection: High over Low and Low over High-pressure safeguards.
- Material Composition: Aluminium, Brass, or 316/316L Stainless Steel body with wetted parts made from 316 Stainless Steel, Ceramic Magnet, and Teflon bushings.
- Switch Configurations: SPDT (3W, 0.25 Amp, 125 VAC/VDC) or SPST (25W, 0.5 Amp, 230 VAC/VDC) options available.
- Transmitter Features: Microprocessor-based 4-20 mA transmitter with ±2% accuracy (20%-100% of scale). CE-marked upon request.
- Dial Sizes: Available in 2-1/2”, 4-1/2”, and 6” diameters.
- Working Pressure: Handles up to 1000 PSIG (69 Bar).
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Model 116 Bellows Type Tank Level Gauge
- Accuracy: ±1% Full Scale Ascending Accuracy (ASME B40.1 Grade 1A).
- Dial Size: 6” diameter with white lettering on black dial (optional white dial with black lettering available).
- Dial Scale Ranges: 0-70” H₂O to 0-800” H₂O; scales available for LOX, Ar, O₂, N₂, CO₂, CM H₂O, MM H₂O, etc.
- Operating Temperature: -40°C to +93°C.
- Working Pressure: Rated at 500 PSIG (34 Bar), optional at 1000 PSI (69 Bar).
- Construction Material: Brass body with 316 Stainless Steel internals. Optional O-rings available in Buna-N, Viton, and Ethylene Propylene.
- Weather Resistance: Built for tough environments with corrosion-resistant gauge front.
- Lens Type: Shatter-resistant.
- Over-Range Protection: Bi-directional over-pressure relief valve safeguards both High and Low sides.
- Switch Options: One or two independently adjustable SPDT switches configurable for increasing or decreasing pressure.
- Outputs: 4 AMP @ 30 VDC, 3 AMP @ 240 VAC, 5 AMP @ 120 VAC.
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Model 130 Delta Gauge®
- Wide Selection of DP Ranges & Scales
- Elastomer Diaphragm Sensing Element, No Cross Port Leakage
- Up to 500 PSIG Working Pressure (34 bar)
- Over-Range Protection, High over Low and Low over High
- Gauge Housings available in Aluminum, Brass, 316/316L Stainless Steel and Polysulfone Thermoplastic
- Wide Range of elastomers
- Over-range Protection – Full to Maximum Working Pressure
- Panel Mounting – Standard
- Pipe Mounting Kit – Optional – 2″ U-Bolt
- Wall Mounting – Optional – Rear Mount
- NACE Compliance – Optional
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Model 140 Delta Meter®
- DP Ranges from 0-25 PSID to 0-100 PSID
- Elastomer Diaphragm Sensing Element,
No Cross Port Leakage - Up to 3000 PSIG Working Pressure (200 bar)
- Over-Range Protection,
High over Low and Low over High - Gauge Housings available in Aluminum, Brass, 316/316L Stainless Steel and Acetal Plastic
- Wide Range of Elastomers
- Over-range Protection Full to Maximum Working Pressure
- Panel Mounting Standard, Front or Rear Panel
- Pipe Mounting Kit Optional – 2″ U-Bolt
- Wall Mounting Optional – Rear Mount
- NACE Compliance Optional
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Model 142 Delta Meter®
- DP Ranges from 0-20” WC to 0-25 PSID
- Elastomer Diaphragm Sensing Element, No Cross Port Leakage
- Up to 3000 PSIG Working Pressure (200 bar)
- Over-Range Protection, High over Low and Low over High
- Gauge Housings available in Aluminum, Brass, 316/316L Stainless Steel and Acetal Plastic
- Wide Range of Elastomers
- Over-range Protection Full to Maximum Working Pressure
- Panel Mounting Standard, Front or Rear Panel
- Pipe Mounting Kit Optional – 2″ U-Bolt
- Wall Mounting Optional – Rear Mount
- NACE Compliance Optional
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Model 146 Differential Pressure Indicator / Switch
- Differential Pressure Range 0-50″ H2O (0-125 mbar) to 0-30 PSID (0-2.0 bar)
- Accuracy ±5% F.S.
- Dial Size
- Single 1-1/4″ x 2-1/4″ Oval (Std.)
- Dual 1-1/4″ x 2-1/4″ Oval (Opt.)
- Working Pressure 1,000 PSIG (70 bar)
- Operating Temp. -40ºC to +93ºC
- Body Material – Aluminium, Brass, 316/316L
- Internal Materials – 316 Stainless Steel
- Elastomers Buna-N (Std), Viton®* , Neoprene, Ethylene-Propylene, Silicone
- Switch Option
- SPDT 3W, 125 VAC/VDC, 0.25 Amp
- SPST 60W, 240 VAC/VDC, 3 Amp
- Switch Mounting Pre-set in Tube, Flat Pack, Din Connector
- Process Connections
- 1/8″ FNPT Back Conn. (Opt.)
- 1/8″ FNPT Bottom Conn. (Std.)
- Viton® is a Registered Trademark of DuPont Dow Elastomers
Mid-West Model 522
- DP Ranges from 0-5 PSD to 0-50 PSID
- Elastomer Diaphragm Sensing Element
- Up to 1000 PSIG Working Pressure (69 bar)
- Maximum DP Pressure: (High to Low) 200 PSID
- Gauge Housings available in Aluminum, 316/316L Stainless Steel and Acetal Plastic
- Buna-N and Viton Elastomers
- Standard: Panel Mounting, Front or Rear Panel
- Optional: (2) 10-32 Mounting Holes on back of gauge body – 1.75″ Apart x .330″ Depth
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Model 522 Colour
- 3-Color, Green Clean/Yellow Change/Red Dirty
- DP Ranges from 0-5 PSD to 0-50 PSID
- Elastomer Diaphragm Sensing Element
- Up to 1000 PSIG Working Pressure (69 bar)
- Gauge Housings available in Aluminum, 316/316L Stainless Steel and Acetal Plastic
- Buna-N and Viton Elastomers
- Standard: Panel Mounting, Front or Rear Panel, (2) 10-32 Mounting Holes on back of gauge body – 1.75″ Apart x .330″ Depth
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.
Mid-West Models 700, 710 & 715
- Available Ranges:
0-5 PSID (0.35 bar) to 0-300 PSID (0-20.0 bar) - Use with Liquid or Gas media compatible with material of construction
- Full stainless steel construction, compact size, easy installation
- Laser welded, fully-sealed construction: NEMA 4X (IP65)
- Utilizes Piezoresistive Differential Pressure Sensor Isolated Diaphragm
- Zero Adjust / Potentiometer ±5%
- Span Adjustable / Potentiometer ±5%
- CE Certified to EMI / EMC Directive
- LCD or LED display available upon request(Available with DIN Connector & 4-20mA Output only, 2-Wire 20-28 VDC)
- Maximum Overpressure:
(+) Hi-Side equals 2 times specified DP range - Maximum Overpressure:
(-) Low-Side is equal to specified DP range - Maximum Static Pressure 2,900 PSI
- Operating temperature limits – 25.56° C to 79.44° C.
- Storage temperature is -40° C to 93.33° F
- Sensor is temperature compensated from 0° C to 50° C.
- Model 700 is Manufactured in China
Mid-West Model 240
- Accuracy: ±3/2/3% differential full-scale ascending accuracy (ASME B40.1 Grade B).
- Dial Size: 4½” diameter with shatter-resistant lens.
- Dial Scale Ranges: 0–20” H₂O to 0–100 PSID; custom PSI, bar, mbar, kPa, kg/cm², and dual scales available.
- Hazardous Location
- Certifications: CSA, UL, ATEX, and IECEx certified; Class I & II, Divisions 1 and 2; Ex d IIB + H₂, Ex tb IIIC, IP65.
- Operating Temperature: -40°F to +185°F (-40°C to +85°C); output-option temperature limits apply.
- Working Pressure: 1,500 PSI (100 bar); ATEX / IECEx models up to 2,900 PSI SWP.
- Construction Material: Aluminum and 316 stainless steel body with 316 stainless steel wetted parts and ceramic magnet.
- Case Construction: Glass-reinforced thermoplastic case; optional anodized aluminum case.
- Elastomer Options: Buna-N, Viton, or Ethylene Propylene.
- Process Connections: ¼” FNPT or ½” FNPT.
- Weather Resistance: Corrosion-resistant, weather-resistant construction for demanding industrial environments.
- Over-Range Protection: Bi-directional high-over-low and low-over-high protection.
- Switch Options: One or two independently adjustable switches; no power required for switch operation.
- Outputs: SPDT, SPST, DPDT relay, and loop-powered 4–20 mA transmitter options.
- Terminal Strip: Field-accessible terminal strip with ½” FNPT conduit interface.
- Additional Options: Oxygen cleaning, maximum follower pointer, CRN registration, and 2” U-bolt pipe mounting kit.
- Warranty: 5-year warranty.
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WANT MORE TECHNICAL DETAILS? DOWNLOAD OUR DATASHEET.