Product specifications

Phone: [phone] • Fax: [phone] • setra.com ©2014 Setra Systems, Inc. All rights reserved. The Setra Systems name and logo are registered trademarks of Setra Systems, Inc.
DIFFERENTIAL PRESSURE
32
Model 239
High Accuracy, Low-Dierential Pressure Transducer
FEATURES
±0.14% FS Accuracy
Fast Warm-Up
Low Thermal Eects
Fast Response Time (<10ms)
Withstands High Overpressure
RoHS Compliant
Meets CE Conformance Standards
APPLICATIONS
HVAC Control
Leak Detection
Environmental Testing
Medical Instrumentation
Energy Management
Clean Rooms
DESCRIPTION
The Model 239 Series pressure transducers are designed for
very low pressure applications that require high accuracy.
The variable capacitance sensor is design to be simple and re-
liable. The stainless steel diaphragm and insulated electrode
form a variable capacitor. As pressure increases or decreases,
the capacitance changes. This change is detected and con-
verted to a linear DC electric signal by Setra’s unique electronic
circuit.
The Model 239 series is available in a voltage or current output.
High positive overpressure protection is achieved by the sen-
sor electrode acting as a stop for the diaphragm. The high level
output signals, excellent long term stability, and fast dynamic
response make these transducers ideal for a wide range of in-
dustrial, laboratory and aerospace applications.
SPECIFICATIONS
Performance Data Physical Description Electrical Data (Voltage)
Accuracy RSS at constant temp* ±0.14% FS Pressure Fittings 1/8”- 27NPT internal Circuit 4-Wire (+Exc, -Exc, +Out, -Out)
Non-Linearity, BFSL ±0.10% FS Electrical Connection 2’ Multiconductor Cable Excitation* 22 to 30 VDC (reverse excitation protected)
Hysteresis 0.10% FS Weight (approx) 8 oz Output Impedance <10 ohms
Non-Repeatability 0.02% FS Vibration 2g from 5 Hz to 500 Hz Output Noise <200 microvolts RMS (in band, 0Hz to 10kHz)
Warm-Up Shift <±0.1% FS residual
shift after 5 minutes
Internal Volumes Positive port 0.03 in
3
Reference port 0.1 in
3
Output** See Ordering Information (for unidirectional ranges)
±2.5 VDC (for bidirectional ranges)
Settling Time <100 ms Max Volume Change at FS 0.001 in
3
*Internal regulation minimizes eect of excitation variation, with <±0.005% FS output change.
Will operate on 28VDC aircraft power per MIL-STD-704A & not be damaged by emergency power
conditions.
**Calibrated into 50K ohm load. Operable into 5000 ohms or greater.
***Zero output factory set to within ±20mV
Acceleration Response <0.0002 psi/g
Acceleration 10g Max
Natural Frequency 2000 Hz nominal Shock 50g Operating
Operable Line Pressure Vacuum to Max 250 PSIG
Environmental Data Electrical Data (Current)
Line Pressure Eect 2%/100 PSI Temperature Circuit 2-Wire
Thermal Eects** Operating ºF (ºC) 0 to +175 (-18 to +80) Output* 4 to 20 mA**
Compensated Range ºF (ºC) +30 to +150 (-1 to +65) Storage ºF (ºC) -65 to +250 (-55 to +120) External Load 0 to 1000 ohms
Zero Shift %FS/100ºF(50ºC) <+1 (<±0.9)
Pressure Media
Min. Supply Voltage (VDC) 17 + 0.02 x (resistance of receiver plus line)
Span Shift %FS/100ºF(50ºC) <+1 (<±0.9) Positive Pressure Media: Gases compatible with stainless
steel, hard anodized 6061 aluminum (Buna-N O-ring)
Max. Supply Voltage (VDC) 42 + 0.004 x (resistance of receiver plus line)
*RSS of Non-Linearity, Non-Repeatability and Hysteresis
**Units calibrated at nominal 70ºF. Maximum thermal error computed from this
datum. x 2 for 0.5 and ±0.25 in. W.C. ranges.
Eect of Power Supply
Reference Pressure Media: Clean dry air or other gases (non-
corrosive, non-condensable)
Variations <0.003 mA/Volt
Output Noise <10 microamperes RMS (0Hz to 10kHz)
Specications subject to change without notice
*Calibrated at factory with a 24 VDC loop supply voltage and a 250 ohm load.
** Zero output factory set to within ±0.07 mA. Span (FS) output factory set to within ±0.07 mA.