The BAPI ZPS-LR-EZ-ST-IN is a Low Range EZ Pressure Sensor — a true differential pressure transmitter rated -1 to +1″ WC (-250 to +250 Pascals) and selectable across 10 field-selectable ranges and five field-selectable outputs (4 to 20 mA, 0 to 5 V, 1 to 5 V, 0 to 10 V, 2 to 10 V). Range, output, direction (uni- or bi-directional) and display units are all set on the front-panel rotary switch and NEXT button, so one part number covers a wide span of zone, duct static and filter differential applications. This unit is ordered in Inches WC display units and ships with a static pressure probe included.
Specifications on this page are taken from the BAPI EZ Pressure Sensor (ZPS) datasheet, Rev. 03/03/26, and the Low Range installation and operation instructions, rev. 06/08/2026. The agency listing (RoHS, UL, CE EN 61326-1:2013 EMC) is taken from the instruction sheets; the Rev. 03/03/26 datasheet lists RoHS and CE only.
Documented Applications
- Air filter pressure drop monitoring, with a static pressure probe on each side of the filter bank
- Duct static pressure monitoring, with a static pressure probe in the duct
- Zone pressure sensing — BAPI catalogs the EZ Pressure Sensor in its Zone Pressure Sensors (ZPS) family
- Panel installations where space is tight — BAPI states the unit is about one third the size of a field mount pressure sensor
BAPI illustrates air filter pressure drop and duct static pressure monitoring in the installation instructions. Confirm suitability for any other application against BAPI before specifying.
Key Features
10 Field-Selectable Ranges
Rotary switch positions R1 through R5, each carrying a unidirectional and a bidirectional option, give ten ranges from 0 to 0.10″ WC up to -1.00 to 1.00″ WC without changing part numbers.
Five Selectable Outputs
Set 4 to 20 mA, 0 to 5 V, 1 to 5 V, 0 to 10 V or 2 to 10 V from the OUT position on the rotary switch. All five are available on every pressure range.
Inches WC or Pascals
The UNIT position toggles the display between inches of water column and Pascals. Pascal equivalents run to -250 to 250 Pa on this range class.
Low Range Accuracy
±0.25% FS at 77°F (25°C) or ±0.005″ WC (±1.24 Pa), with a total error band of ±1.25% FS or ±0.025″ WC (±6.22 Pa) — typical accuracy within the compensated range of 32 to 122°F (0 to 50°C), after initial start-up and auto-zero.
Three Ways to Mount
Blue mounting tabs pull out for DIN rail or surface mounting and push in for 2.75″ Snaptrack. The unit is about one third the size of a field-mount pressure sensor, so it fits where panel space is tight.
Static Pressure Probe Included
BAPI's ordering guide lists a static pressure probe included with this part number, so the duct pickup is covered in a single line item. Pressure ports are 3/16″ (4.75 mm) barbed fittings.
Technical Specifications
| Specification | Value |
|---|---|
| Sensor Type | True differential pressure transmitter |
| Pressure Ranges (inches WC) | 0 to 0.10″, 0 to 0.25″, 0 to 0.50″, 0 to 0.75″, 0 to 1.00″, -0.10 to 0.10″, -0.25 to 0.25″, -0.50 to 0.50″, -0.75 to 0.75″, -1.00 to 1.00″ |
| Pressure Ranges (Pascals) | 0 to 30 Pa, 0 to 50 Pa, 0 to 100 Pa, 0 to 175 Pa, 0 to 250 Pa, -30 to 30 Pa, -50 to 50 Pa, -100 to 100 Pa, -175 to 175 Pa, -250 to 250 Pa |
| Sensor Span | -1 to +1″ WC (-250 to +250 Pascals) |
| Output Signals | 4 to 20 mA, 0 to 5 VDC, 1 to 5 VDC, 0 to 10 VDC, 2 to 10 VDC (field selectable) |
| Directionality | Uni-directional or bi-directional, field selectable |
| Display Units Ordered | Inches WC (field selectable) |
| Power Supply | 8 to 40 VDC (4 to 20 mA); 7 to 40 VDC or 6 to 28 VAC (0 to 5 or 1 to 5 VDC); 12 to 40 VDC or 9 to 28 VAC (0 to 10 or 2 to 10 VDC) |
| Power Consumption | 20 mA max DC at 4 to 20 mA; 4.9 mA max DC or 0.12 VA max AC at 0 to 5 or 0 to 10 VDC |
| Load Resistance | 850 ohm maximum @ 25 VDC (4 to 20 mA); 6 kohm minimum (voltage outputs) |
| Wiring | 3 wires (2 wires for 4 to 20 mA output) |
| Accuracy | ±0.25% FS at 77°F (25°C) or ±0.005″ WC (±1.24 Pa) |
| Total Error Band | ±1.25% FS or ±0.025″ WC (±6.22 Pa) — typical accuracy within the compensated range of 32 to 122°F (0 to 50°C), after initial start-up and auto-zero |
| Temperature Hysteresis & Stability | ±0.35% at 77°F (25°C) for 1000 hours |
| Overpressure | Proof 270″ WC (67 kPa) |
| Media | Clean, dry, non-corrosive gases |
| Pressure Ports | 3/16″ barb (4.75 mm) |
| Display | Integrated display, reads pressure over the entire operational range |
| Operating Environment | 14 to 131°F (-10 to 55°C), 0 to 95% RH, non-condensing |
| Storage Temperature | -4 to 140°F (-20 to 60°C) |
| Enclosure Material | ABS plastic, UL94 V-0 |
| Mounting | DIN rail, 2.75″ Snaptrack, or surface |
| Dimensions | 1.94″ (49.2 mm) W x 1.89″ (48 mm) D x 3.35″ (85 mm) H |
| Agency | RoHS, UL, CE EN 61326-1:2013 EMC |
| Calibration Certificate | NIST traceable certificate available at no charge |
| Included Accessories | Static Pressure Probe Included |
| Warranty | 5 years |
Documentation
Specifications are subject to change without notice. Always confirm against the current BAPI datasheet before ordering.
Related Products
Companion unit supplied without a tube or probeBAPI ZPS-SR-EZ-ST-IN
Standard Range version of this sensorAll Dry Differential Pressure Transmitters
Browse the full ZOT Supply range
Frequently Asked Questions
What pressure ranges can the ZPS-LR-EZ-ST-IN be set to?
Ten ranges are available on the rotary switch: 0 to 0.10″ WC, 0 to 0.25″ WC, 0 to 0.50″ WC, 0 to 0.75″ WC, 0 to 1.00″ WC, -0.10 to 0.10″ WC, -0.25 to 0.25″ WC, -0.50 to 0.50″ WC, -0.75 to 0.75″ WC, -1.00 to 1.00″ WC. In Pascal display mode the same positions read 0 to 30 Pa, 0 to 50 Pa, 0 to 100 Pa, 0 to 175 Pa, 0 to 250 Pa, -30 to 30 Pa, -50 to 50 Pa, -100 to 100 Pa, -175 to 175 Pa, -250 to 250 Pa.
Which outputs can I select on this unit?
All five outputs are available on every range: 4 to 20 mA, 0 to 5 VDC, 1 to 5 VDC, 0 to 10 VDC and 2 to 10 VDC. Move the rotary switch to OUT and press NEXT until the desired output shows, then return the switch to the pressure range position.
What is the start-up and auto-zero procedure?
Let the sensor acclimate for 24 hours with no pressure applied. Then power it, deadhead the ports and leave it in the desired range for 60 minutes. To auto-zero, tie the high and low ports together with a short unkinked tube, move the rotary switch to the 0 position (the display reads Aut0), press NEXT, and wait for donE. BAPI recommends re-zeroing 2 to 3 times a year on critical applications.
How accurate is the ZPS-LR-EZ-ST-IN?
Accuracy is ±0.25% FS at 77°F (25°C) or ±0.005″ WC (±1.24 Pa). The total error band, which covers non-linearity, hysteresis and thermal effect on span, is ±1.25% FS or ±0.025″ WC (±6.22 Pa) — typical accuracy within the compensated range of 32 to 122°F (0 to 50°C), after initial start-up and auto-zero.
Does a tube or probe come with this part number?
Yes. BAPI's ordering guide lists a static pressure probe included with this part number. The sensor ports are 3/16″ (4.75 mm) barbed fittings. BAPI recommends forming a drip loop in the tubing so condensation cannot reach the sensor.
Where can this sensor be mounted?
DIN rail, 2.75″ Snaptrack, or directly to a surface or panel backplane. Pull the blue mounting tabs out for DIN rail and surface mounting, or push them in for Snaptrack. Surface mounting uses 1/8″ pilot holes and #8 flathead screws.
How much overpressure can it take?
Proof overpressure is 270 in WC (67 kPa) for this range class. Media must be clean, dry, non-corrosive gases.
Building Automation Products, Inc. shows a 5 year warranty for the EZ Pressure Sensor (ZPS) family on the product datasheet, Rev. 03/03/26. BAPI notes that improper supply voltage, polarity, or wiring connections may damage the product and void the warranty. Full warranty terms are set by BAPI. ZOT Supply is an authorized BAPI distributor and can assist with warranty claims and application support.
- Series:
- ZPS Series
- Pressure Range Class:
- Field Selectable
- Pressure Range:
- Field Selectable to +/-1.00 in WC
- Direction:
- Field Selectable
- Output Signal:
- Field Selectable
- Display:
- Integrated
- Accuracy Class:
- High (0.5% FS or better)
- Mounting:
- DIN Rail
- Included:
- Static Pressure Probe
- Made in USA:
- Unspecified
