Pressure Measurement

Differential Pressure Transducer

Model 267/267MR (HVAC Application)

setra model 267 differential pressure transducer hvac application


Setra’s Model 267 and 267MR Differential Pressure Transducer sense gauge (static) or differential pressure and convert this pressure difference to a proportional electrical output. The 267 series is offered with a high level voltage output or 4-20 mA current output. The 267MR offers multi-range capability and field configurable 0-5 VDC or 0-10 VDC output, as well as a 4-20 mA output.

In a typical Setra configuration, Model 267 and 267MR has a compact housing contains two closely-spaced, parallel, electrically-isolated metallic surfaces, one of which is essentially a diaphragm capable of slight flexing under applied pressure. The diaphragm is constructed of low-hysteresis material such as 17-4 PH SS or a proprietary compound of fused glass and ceramic (Setraceramâ„¢). These firmly secured surfaces (or plates) are mounted so that a slight mechanical flexing of the assembly, caused by a minute change in applied pressure, alters the gap between them (creating, in effect, a variable capacitor). The resulting change in capacitance is detected by a sensitive linear comparator circuit (employing proprietary, custom-designed ASICs), which amplifies and outputs a proportional, high-level signal.

  • Model 267MR Offers Multi-Range Capability, 6 Field Selectable Ranges via Dip Switches, and Field Selectable 0-5 or 0-10 VDC Output
  • Model 267 Offers an Optional 3 1/2 Digit LCD Display with a 0.5% FS Standard Accuracy
  • NEMA 4/IP65 Rated Housing
  • Optional accuracy as high as 0.25% full scale
  • 24 VAC or 24 VDC Excitation
  • PG-9, PG13.5 or Conduit Electrical Termination
  • Integral Static Pressure Probe
  • Ranges as low as 0.1 in. W.C. (25 Pa)
  • Meets CE Conformance Standards
Model 267 and 267MR is used in the following applications:
  • Heating, Ventilating and Air-Conditioning (HVAC)
  • Energy Management Systems
  • Static Duct Pressure
  • Clean Room Pressure
  • Oven Pressurization and Furnace Draft Controls

Technical Details

Accuracy* RSS (At Constant Temp.)±1.0% FS±0.4% FS ±0.25% FS
Non-Linearity, BFSL±0.98% FS±0.38% FS ±0.22% FS
Hysteresis0.10% FS0.10% FS 0.10% FS
Non-Repeatability0.05% FS0.05% FS 0.05% FS
Thermal Effects**
Compensated Range °F(°C)+40 to +150 (+5 to +65)
Zero/Span Shift %FS/°F(°C)±0.033 (±0.06)
Maximum Line Pressure10 PSI
Overpressure10 PSI in Positive or Negative Direction
Warm-up Shift±0.1% FS Total
Position Effect**
RangeTo 0.5 in. / To 1.0 in. / To 2.5 in. / To 5.0 in.
*RSS of Non-Linearity, Non-Repeatability and Hysteresis.
**Units calibrated at nominal 70°F. Maximum thermal error computed from this datum.
***Unit is factory calibrated at 0g effect in the vertical position.

Physical Description

CaseFire-Retardant Glass Filled
Polyester (UL 94 V-0 Approved)
MoutingFour screw holes on removable
zinc plated steel base (designed
for 2.75” snap track)
Electrical ConnectionScrew Terminal Strip
Electrical TerminationPG-9/PG13.5 Strain Relief, 1/2″
Conduit Opening, or 9 Pin D-Sub
Zero and Span AdjustmentsAccessible on top of case
Display (Optional on 267 only)3 1/2 Digit LCD Integral
Display(1.74″W x 0.78″H)
Pressure Fittings3/16″ O.D. Barbed Brass for 1/4″
Push-On Tubing (Standard)
Static Pressure Probe (Optional)
1/4″ NPTF Brass (Optional)
Mounting2 Mounting Tabs with 0.18″ Holes
Pressure Probe Assembly is Supplied
with a 7.8″ 6061 Aluminum Alloy
Probe and a Gasket to Seal Against
the Duct
Weight (Approx.)9.0 ounces (255 grams)
9.5 ounces (Duct Probe Assembly)
*9 pin D-sub Connector is not suitable for NEMA4/IP-65 environments.

Electrical Data (Voltage)

Circuit3-Wire (Exc, Gnd, Sig)
Protected from Miswiring
Excitation (for 0-5 VDC Output)9 to 30 VAC/12 to 40 VDC
Excitation (for 0-10 VDC Output)11 to 30 VAC/13 to 40 VDC
Model 267
Output*0 to 5 VDC**
0 to 10 VDC**
Model 267MR
Output* (Field Selectable)0 to 5 VDC**
0 to 10 VDC**
Bidirectional Output at ZeroMid-Range of Specified Output
Output Impedance100 Ohms
Re-Ranging (267MR only)5 Position Dip Switches
(Located Inside Case)
*Calibrated into a 50K ohm load, operable into a 5000 ohm load or greater.
**Zero output factory set to within ±50mV (±25 mV for optional accuracies).
Span (Full Scale) output factory set to within ±50mV. (±25 mV for optional accuracies).

Electrical Data (Current)

Protected from Miswiring
Output*4 to 20 mA**
Bidirectional Output at Zero12 mA
External Load0 to 800 Ohms
Minimum loop supply voltage (VDC) = 9 + 0.02 x (Resistance of receiver plus line).
Maximum loop supply voltage (VDC) = 30 + 0.004 x (Resistance of receiver plus line).
Re-Ranging (267MR only) 4 Position Dip Switches (located inside case)
*Calibrated with a 24 VDC loop supply voltage and a 250 ohm load
**Zero output factory set to within ±0.16mA (±0.08 mA for optional accuracies)
Span (Full Scale) output factory set to wtihin ±0.16mA (±0.08 mA for optional accuracies)

Pressure Media

Typically Air or Similar Non-Conducting Gases

Environmental Data

Operating* °F (°C)0 to +150 (-18 to +65)
Storage °F (°C)-65 to +180 (-54 to +82)
*Operating temperature limits of the electronics only.
Pressure media temperature may be considerably higher or lower.

Note: Specification are Subject to change without notice