The ACI A/MLP2-040-W-B-A-A-0P is a miniature low differential air pressure transmitter built for OEM equipment and high-density control panels. It senses +/-40 in WC bidirectional (negative and positive) and outputs a linear 4-20 mA signal proportional to the applied differential. The piezoresistive silicon sensing element delivers +/-0.5% FSO typical accuracy (including hysteresis, linearity, and repeatability) at 71 F, with a front-cover pushbutton zero for in-place re-zeroing after warm-up. The 4.210 x 2.085 x 1.340 in polycarbonate enclosure mounts to 35 mm DIN rail (rear or side-clip) or panel-screws to a flat surface in seconds.
WARRANTY
Key Features
Piezoresistive Silicon Sensing
Solid-state silicon sensing element delivers low warm-up shift, low long-term drift, and high resolution at very low pressures. The sensor is internally isolated from package stress for stable readings across temperature.
4-20 mA Output
Provides a linear 4-20 mA signal proportional to the applied differential pressure. 2-wire loop-powered or 3-wire vac-powered. Output limited to 20.5 mA maximum. Compatible with virtually any BAS or DDC analog input.
+/-0.5% FSO Accuracy
Total accuracy spec includes hysteresis, linearity, and repeatability at 71 F typical. Thermal effects are +/-0.056% FSO/F (+/-0.10% FSO/C) referenced to 77 F. Compensated temperature range is 32 to 122 F.
Front-Cover Pushbutton Re-Zero
A press-and-hold pushbutton on the front face allows the transmitter to be re-zeroed in-place after the 15-minute warm-up - no need to open the enclosure or apply known reference pressure. Periodic re-zeroing eliminates the effect of stress-relaxation drift over time.
Dual DIN Rail or Panel Mount
Integrated rear 35 mm DIN rail foot (U.S. Patent No. 7,416,421) snaps directly onto standard rail; an included side-clip adapter offers a thinner profile for high-density panels. Two #8 self-drilling screws (included) allow flat-surface panel mounting instead.
Robust Overpressure Protection
Proof pressure: 562 in WC (140 kPa). Burst pressure: 1004.7 in WC (250 kPa). Substantial overpressure margin protects against duct surge events, fan startup transients, and accidental mis-plumbing of high/low ports during commissioning.
Technical Specifications
| Specification | Value |
|---|---|
| Model | A/MLP2-040-W-B-A-A-0P |
| Pressure Range | +/-40 in WC |
| Direction | Bidirectional (negative and positive) |
| Accuracy | +/-0.5% FSO typical (includes hysteresis, linearity, repeatability at 71 F) |
| Output Signal | 4-20 mA, 2-wire loop-powered or 3-wire VAC-powered |
| Supply Voltage | 16-36 VDC (250 ohm load) / 21-36 VDC (500 ohm load) / 24 VAC +/-10% 50/60 Hz |
| Supply Current | 23 mA minimum (0.83 VA) |
| Output Limit | Output limited to 20.5 mA maximum |
| Sensor Type | Piezoresistive silicon |
| Sensor Compensated Temperature | 32 to 122 F (0 to 50 C) |
| Thermal Effects | +/-0.056% FSO/F (+/-0.10% FSO/C), referenced to 77 F |
| Warm-Up Time | 15 minutes |
| Response Time (T95) | 4 seconds |
| Output Update Rate | 500 ms |
| Zero Function | Front-cover pushbutton (recommended after 15-minute warm-up) |
| Proof Pressure | 562 in WC (140 kPa) |
| Burst Pressure | 1004.7 in WC (250 kPa) |
| Operating Temperature | 32 to 185 F (0 to 85 C) |
| Operating Humidity | 10 to 95% RH, non-condensing |
| Storage Temperature | -40 to 176 F (-40 to 80 C) |
| Enclosure Temperature Rating | -40 to 248 F (-40 to 120 C) |
| Enclosure Material | Polycarbonate, UL 94 V-0 flame rating |
| Media | Dry air and other non-corrosive, non-ionic gases |
| Pressure Fittings | Brass push-on, 0.250 in (6.35 mm) OD x 0.170 in (4.318 mm) ID poly tubing |
| Wiring | 3-position de-pluggable screw terminal block, 14-24 AWG shielded |
| Terminal Torque | 4.43 to 5.31 in-lbs (0.5 to 0.6 Nm) |
| DIN Rail Mounting | 35 mm rear-integrated, side-clip adapter included (U.S. Patent No. 7,416,421) |
| Dimensions (L x W x D) | 4.210 x 2.085 x 1.340 in (106.94 x 52.96 x 34.04 mm) |
| Weight | 0.17 lb (0.078 kg) |
| NIST Certification | No NIST Certificate (factory-calibrated using NIST-traceable equipment) |
| Approvals | CE, RoHS2, WEEE, REACH, UKCA |
| Country of Origin | Made in USA - Middleton, Wisconsin |
| Warranty | 5-year limited |
| Manufacturer Part Number | A/MLP2-040-W-B-A-A-0P |
Documentation
Frequently Asked Questions
What pressure range does the A/MLP2-040-W-B-A-A-0P measure?
How is the 4-20 mA output wired?
How and when should I re-zero the transmitter?
What media can this transmitter measure and how should I mount it?
Does the A/MLP2-040-W-B-A-A-0P ship with a NIST certificate?
- Brand:
- ACI
- Series:
- MLP2
- Product Type:
- Miniature Low Differential Air Pressure Transmitter
- Pressure Range:
- +/-40 in WC
- Range Code:
- 040
- Direction:
- Bidirectional (negative and positive)
- Output Signal:
- 4-20 mA
- Output Wiring:
- 2-wire loop-powered or 3-wire VAC-powered
- Supply Voltage:
- 16-36 VDC (250 ohm load) / 21-36 VDC (500 ohm load) / 24 VAC +/-10% 50/60 Hz
- Supply Current:
- 23 mA minimum (0.83 VA)
- Accuracy:
- +/-0.5% FSO typical (includes hysteresis, linearity, repeatability)
- Sensor Type:
- Piezoresistive silicon
- Sensor Compensated Temperature:
- 32 to 122 F, 0 to 50 C
- Thermal Effects:
- +/-0.056% FSO/F
- Warm-Up Time:
- 15 minutes
- Response Time T95:
- 4 seconds
- Output Update Rate:
- 500 ms
- Zero Function:
- Front-cover pushbutton
- Proof Pressure:
- 562 in WC (140 kPa)
- Burst Pressure:
- 1004.7 in WC (250 kPa)
- Operating Temperature:
- 32 to 185 F, 0 to 85 C
- Operating Humidity:
- 10 to 95% RH non-condensing
- Storage Temperature:
- -40 to 176 F, -40 to 80 C
- Media:
- Dry air and non-corrosive, non-ionic gases
- Pressure Fitting:
- Brass push-on, 0.250 in OD x 0.170 in ID tubing
- Wiring:
- 3-position de-pluggable terminal block, 14-24 AWG shielded
- Mounting:
- 35 mm DIN rail (rear or side-clip) or panel-screw
- Enclosure:
- Polycarbonate, UL 94 V-0
- Dimensions:
- 4.210 x 2.085 x 1.340 in
- Weight:
- 0.17 lb, 0.078 kg
- NIST Certification:
- No NIST Certificate
- Approvals:
- CE, RoHS2, WEEE, REACH, UKCA
- Country of Origin:
- USA (Middleton, Wisconsin)
- Warranty:
- 5-year limited
