The Dwyer Series MSX Pro MSXP-W12-PA-LCD is a Magnesense differential pressure transmitter built for critical building performance applications - filter monitoring, duct static pressure, clean room and isolation room differential, air velocity and flow measurement in VAV systems, and other commercial HVAC and BAS work where stability and long-term accuracy matter. This is the 0 to 5 in WC (1250 Pa / 125 mm WC) unidirectional wall-mount configuration with factory-default Pascals display units. +/-0.5% FSO typical accuracy, +/-1% FSO/year long-term stability. The MSX Pro carries a NEMA 4X / IP66 rating with plenum-rated (UL 2043) and UL94 V-0 flame-rated housing. This SKU includes the optional 4-digit LCD display, which mounts on top of the PCB and is 180° rotatable so it reads correctly whether the unit is installed with ports facing down or up.
WARRANTY
Key Features
Magnesense Pressure Sensing
Built on Dwyer's Magnesense sensing platform - the same technology used in the original MS2 Magnesense II. Delivers exceptional long-term stability (+/-1% FSO per year) for critical building performance applications where drift over time matters more than initial accuracy.
Dual Simultaneous Output
Provides BOTH a 4-20 mA current output AND a 0-5/0-10 VDC voltage output from the same unit at the same time. One signal can drive the BAS analog input while the second goes to a panel meter or chart recorder for verification. Rare feature in this class - useful when commissioning needs redundant signal paths.
Field-Selectable Range, Direction, Response
Internal DIP switches set the pressure range (4 sub-options per range tier), unidirectional or bidirectional mode, response time (instantaneous default or 3-second damping), voltage output (0-5 V or 0-10 V), and display units (Pa, mm WC, or in WC). Factory-set per the order code; field-adjustable without returning the unit.
Velocity & Flow with Built-In Square Root
Beyond pressure, the MSX Pro can switch to velocity or flow output mode with the square-root extraction handled in the transmitter itself. Useful for VAV applications, pitot-tube airflow measurement, and CFM totalization without needing a separate signal conditioner. K-factor and duct-area parameters are entered via the front-panel menu (LCD models) or DIP switches.
Flip-Lid + Tamper-Resistant + Toolless Terminal
Hinged flip-lid housing simplifies wiring access; tamper-resistant cover deters field tampering. Liquid-tight cable gland fitting protects the cable egress from moisture, and the toolless removable European-style 4-wire terminal block (16-26 AWG) speeds up installation - no screwdriver needed for the field-side terminals.
4-Digit LCD Display Included
Includes the optional 4-digit LCD display for live pressure, velocity, or flow readout in the configured engineering units. The LCD is 180° rotatable so it reads correctly regardless of mounting orientation. Provides on-board commissioning, diagnostics, and PIN-protected menu access without needing a handheld meter.
Selectable Sub-Ranges
This SKU's Range 2 sensing element supports 4 selectable sub-ranges set by DIP switches 7 and 8 (see the installation manual for the switch positions). The factory full-scale output is the largest value in the table - sub-ranges 1-3 are available without returning the unit.
| DIP Position | Inches WC | Pa (Set 1) | Pa (Set 2) | mm WC |
|---|---|---|---|---|
| 1 | 1 in WC | 250 Pa | 600 Pa | 25 mm WC |
| 2 | 2 in WC | 300 Pa | 750 Pa | 50 mm WC |
| 3 | 3 in WC | 400 Pa | 1000 Pa | 100 mm WC |
| 4 | 5 in WC | 500 Pa | 1250 Pa | 125 mm WC |
Position 4 (5 in WC / 1250 Pa / 125 mm WC) is the factory full-scale value (factory full scale) for Range 2.
Technical Specifications
| Specification | Value |
|---|---|
| Model | MSXP-W12-PA-LCD |
| Series | Series MSX Pro Magnesense |
| Pressure Range (Full Scale) | 0 to 5 in WC (1250 Pa / 125 mm WC) |
| Direction | Unidirectional |
| Mount Type | Wall Mount |
| Selectable Sub-Ranges (in WC) | 1 in WC, 2 in WC, 3 in WC, 5 in WC |
| Selectable Sub-Ranges (Pa - Low Set) | 250 Pa, 300 Pa, 400 Pa, 500 Pa |
| Selectable Sub-Ranges (Pa - High Set) | 600 Pa, 750 Pa, 1000 Pa, 1250 Pa |
| Selectable Sub-Ranges (mm WC) | 25 mm WC, 50 mm WC, 100 mm WC, 125 mm WC |
| Display Unit (Factory Default) | Pascals |
| Display Units (DIP-Selectable) | Pa (low or high set), mm WC, or in WC |
| Accuracy | +/-0.5% FSO for all ranges except unidirectional 0.5 in WC range |
| Stability | +/-1% FSO per year |
| Service / Media | Air and non-combustible, compatible gases |
| Output Signals | 4-20 mA (2-wire) AND 0-10 V or 0-5 V (3-wire), simultaneous |
| Voltage Output Selection | DIP switch 4: 0-10 V (default) or 0-5 V |
| Power Requirements | 10-36 VDC (2-wire current); 17-36 VDC or 21.6-33 VAC isolated (3-wire voltage) |
| Current Consumption | 21 mA max continuous |
| Loop Resistance | Current output: 0-1250 ohms max; Voltage output: 1 kohm minimum load |
| Response Time | Instantaneous (default) or 3 seconds (DIP-selectable) |
| Zero and Span Adjustments | Digital push-button |
| Pressure Limits | 6 psi max operation, 6 psi burst |
| Temperature Limits | -4 to 158 F (-20 to 70 C) |
| Process Connections | 1/8 in, 3/16 in, 1/4 in, 5 mm, and 6 mm ID flexible tubing |
| Electrical Connections | 4-wire removable European-style terminal block, 16-26 AWG |
| Electrical Entry | 1/2 in NPS thread, liquid-tight cable gland included |
| Enclosure Rating | NEMA 4X (IP66); UL 2043 (plenum); UL94 V-0 |
| Mounting Orientation | Pressure sensor measurement unaffected by orientation |
| Display | 4-digit LCD (included) |
| Weight | 8.0 oz (230 g) |
| Compliance | CE |
| Manufacturer | Dwyer Instruments, LLC (DwyerOmega) |
| Manufacturer Part Number | MSXP-W12-PA-LCD |
Documentation
Frequently Asked Questions
What pressure range does the MSXP-W12-PA-LCD measure?
What is dual simultaneous output and when should I use it?
How do I wire the MSX Pro?
What does the LCD show and can I configure it?
How do I install the wall mount version?
How do I switch to velocity or flow output mode?
- Series:
- Series MSX Pro Magnesense
- Pressure Range Class:
- Low (1 to 10 in WC)
- Pressure Range:
- 0 to 5 in WC
- Direction:
- Unidirectional
- Output Signal:
- 4-20 mA + Voltage
- Display:
- LCD
- Accuracy Class:
- High (0.5% FS or better)
- Mounting:
- Wall
- Probe:
- No Probe
- Made in USA:
- Unspecified
