Model 142

Diaphragm Type

Model 142 – Mid-West Instrument convoluted diaphragm type gauge provides a terminal strip interface   to aid in ease of electrical installation of your switch or transmitter. The Model 142 also has the option to add a 4-20 mA transmitter for applications that require constant monitoring. Available with multiple switch options including Hazardous location Class I Div 2 options.  Full scale accuracies of ±3/2/3% (0-20” H2O to 0-25 PSID) are available.  The Model 142 is an accurate and versatile low cost diaphragm type differential pressure gauge/switch or transmitter that will meet  your most demanding DP requirements.

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Product Features/Benefits

  • Rugged Convoluted Diaphragm Design
  • Glass Reinforced Thermoplastic Dial case (Panel Mountable) (Anodized Aluminum Dial Case Option available contact sales for more information)
  • Weather Resistant & Corrosion Resistant
  • Shatter Resistant Lens
  • Over-Range Protection, High over Low and Low over High
  • Terminal Strip Switch & Transmitter Options
  • 5 Year Warranty
  • For complete model details See Bulletin_142.pdf
  • Installation and Operation Manual See Bulletin: IOM_142.pdf

Specifications / Configuration

  • Dial Sizes available: 2-1/2”, 3-1/2”, 4-1/2” and 6” Diameters
  • Dial Scale Ranges: 0-20” H2O to 0-25 PSID (0-50 mbar to 0-1.7 bar)
  • Differential Full Scale Ascending Accuracy ±3/2/3% (ASME B40.1 Grade B)
  • Available in a Variety of Dial Scales: Bar, Mbar, kPa, Kg/Cm2, Dual Scale etc.
  • Working Pressures up to 3000 PSIG (200 Bar)
  • Operating Temp -40°F to +200°F (-40°C to +93°C)
  • Weather Protection NEMA 4X/IP65
  • Material of Construction of Body - Aluminum, Brass, 316/316L Stainless Steel, Aluminum/Bronze & Monel(Wetted Part)
  • Internal wetted parts-316 Stainless Steel, Ceramic Magnet, Teflon Guide Bushings and Monel (Dependent on model chosen)
  • Multiple instrument process connection size and locations available
  • Elastomers (O-ring and Diaphragm Materials) Buna-N, Viton, Ethylene Propylene
  • For complete specifications see: SPECIFICATIONSHEET_142.pdf

Common Applications

  • Filter and Strainer monitoring
  • Compressed Air
  • Hydraulic
  • Refrigerant
  • Pump Performance Testing
  • Heat Exchanger Pressure Drop Monitoring
  • Water Treatment Applications
  • Tank Level Monitoring, Horizontal or Vertical
  • Flow Monitoring & Balancing

Switch Electrical Specifications:

See Bulletin ELECIOM_142

Mid-West Instrument switches are mechanically adjustable allowing customer to set the switch within a defined adjustment span of range of the instrument. Mid-West can also pre-set switch set point(s) upon customer request. All Switches are CE marked per EU Low Voltage and RoHS Directive. Hazardous location and transmitter configurations are enclosed in an Aluminum enclosure and configured  with a ½” FNPT conduit interface.

Mid-West Instrument 142 indicating / non-indicating differential pressure 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 are not CE marked.

  • No Power required to operate switches
  • 1-2 Independent adjustable Switches
  • 4-20 ma Transmitter (8-28 VDC Loop Power) 2% Accuracy (20%-100% of scale, Ascending)
  • Available Switch Output Options
    • SPDT 3W, 0.25 Amp, 125 VAC/VDC
    • SPST 25W, 0.5 Amp, 230 VAC/VDC (Normally Open)
  • Electrical Enclosures Weather-Resistant, NEMA 4X /IP 66
  • Field Wireable terminal Strip
  • Non-Hazardous switches CE Marked in Accordance With Low Voltage & RoHS Directives
  • Hazardous Locations
    • Class I Division I, Groups C & D, Class II, Division I, Groups E, F & G (Not available CE marked)
    • Class I Division II, Groups A, B, C & D, Class II, Division II, Groups F & G

The Mid-West Advantage

“Diaphragm Type” Gauges with Electrical Optional

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
Model 130 0-5" H2O to 0-15 PSID (0-400" H2O) 0-5" H2O to 0-9.9" H2O
±5%
0-10" H2O to 0-15 PSID
±3/2/3%
Up to 500 PSI CE / LVD, RoHS Compliant, NEMA 4X, Class 1-Div. 1
Model 140 0-50" H2O to 0-100 PSID 0-50" H2O to 0-399" H2O
±5%
0-15 PSID to 0-100 PSID
±3/2/3%
Up to 3,000 PSI CE / LVD, RoHS Compliant, NEMA 4X, Terminal Strip, Class 1-Div. 1, Class 1-Div. 2, 4-20mA Transmitter N/A
Model 142 0-20" H2O to 0-25 PSID ±3/2/3% Up to 3,000 PSI CE / LVD, RoHS Compliant, NEMA 4X, Terminal Strip, Class 1-Div. 2, 4-20mA Transmitter
Model 522 0-5 PSID to 0-50 PSID ±5% 1,000 PSI CE / LVD, RoHS Compliant N/A

Electrical “Diaphragm Type” Gauges

Model No. Differential Pressure Range Accuracy Working Pressure Electrical Available Specifications Installation/ Operation Manual Electrical IOM Drawing
Model 240 0-20" H2O to 0-100 PSID ±3/2/3% Up to 1500 PSI CE / ATEX / RoHS Compliant CSA, UL & KOSHA CERTIFIED, NEMA 4X, Terminal Strip, Class 1-Div. 1, Class 1-Div. 2, 4-20mA Transmitter N/A
Model 700 / 710 / 715 0-5 PSID to 0-300 PSID ±0.50% 2,900 PSI 2-Wire
4-20 mA Transmitter 15-28 VDC, LCD = 4-20 mA Transmitter 18-28 VDC, LED = 4-20 mA Transmitter 20-28 VDC
3 Wire
15-28 VDC/1-5 VDC, 15-28 VDC/0-5 VDC, 15-28 VDC/0-10 mADC, 15-28 VDC/0-20 mADC, 15-28 VDC/0-10 VDC
N/A

“Indicator”  Style Diaphragm Type Gauges

Model No. Differential Pressure Range Accuracy Working Pressure Electrical Available Specifications Installation/ Operation Manual Electrical IOM Drawing
Model 522C3-Color Dial 0-5 PSID to 0-50 PSID ±5% 1,000 PSI CE / LVD, RoHS Compliant N/AN/A
Model 555A3-Color Dial 0-3.5 PSID to 0-43 PSID ±5% 300 PSI Not Available N/AN/A