Keyence AP-31K Pressure Sensor Negative NPN

Keyence AP-31K Two-Color Digital Pressure Sensor

Product Introduction

The AP-31K belongs to the Keyence AP-30 series of digital pressure sensors. This negative pressure model uses NPN open collector output and suits vacuum gripping, leak testing, and suction confirmation tasks. Air and non-corrosive gases serve as the working fluid. The gauge pressure design covers a rated range of 0 to -29.9 inchHg. A 3½-digit two-color 7-segment LED display with 11 mm character height makes readings easy to scan on crowded panels.

Technical Specifications

The display system gives the AP-31K its practical edge on the shop floor. Specifically, the two-color LED switches between red and green to flag threshold states at a glance. Resolution reaches 0.1 inchHg, 0.1 kPa, 1 mmHg, or 0.001 bar depending on the selected unit. Meanwhile, response time offers four selectable settings: 2.5, 5, 100, and 500 ms. The chattering prevention function stabilizes readings on pulsating vacuum lines.

The control output handles up to 100 mA at 40 V with 1 V maximum residual voltage. Besides, an analog output of 1 to 5 V supports trend logging on a PLC or recorder. The display temperature characteristic stays within ±1 % of F.S. over 0 to 50 °C.

Mechanical and Environmental Parameters

The housing mixes several materials for durability. Polyamide forms the front housing, while a PET sheet protects the front panel. Polysulfone makes up the rear housing, and die-cast zinc forms the pressure port. An oil-proof cabtyre cable resists lubricant exposure on machine tools.

Operating temperature spans 0 to +50 °C with no freezing. Relative humidity stays within 35 to 85 % RH without condensation. Proof pressure reaches 72.5 PSI, which guards against occasional overpressure events. Vibration resistance covers 10 to 55 Hz at 1.5 mm double amplitude for 2 hours in each X, Y, and Z direction. Protection rating data is not published, so installers should house the unit in a suitable enclosure for wet areas. Weight sits at roughly 120 g.

Installation Guide

First, mount the AP-31K on a flat panel using the rear mounting threads. Keep the pressure port clear of sealant debris. Next, connect the tubing to the die-cast zinc port and secure it with a clamp. After that, wire the supply at 12 to 24 VDC and confirm polarity before power-up. Then set the output mode to N.O. or N.C. as the machine logic requires.

Use the front keys to select units and threshold values. For instance, set the response time to 500 ms on pulsating lines and 2.5 ms on fast pick-and-place heads. Besides, route the cable away from inverter output lines to limit electrical noise. Finally, verify the analog output against a reference gauge and lock the settings.

Packaging List

• 1 × Keyence AP-31K pressure sensor

• 1 × Oil-proof cabtyre cable

• 1 × Mounting bracket and screws

• 1 × Protective packaging

Shipping

Orders ship via Fedex, UPS, DHL. Stock items usually leave the warehouse within 1–2 business days after payment confirmation.

FAQ

Q1: What pressure range does the AP-31K cover?
A: The AP-31K has a rated range of 0 to -29.9 inchHg for negative pressure and a detectable range of -15 to +110 % of F.S.

Q2: Which output type does this model provide?
A: It offers NPN open collector output with two channels, selectable as N.O. or N.C., rated 100 mA at 40 V maximum.

Q3: Can the response time be adjusted?
A: Yes. Users select 2.5, 5, 100, or 500 ms, and the chattering prevention function stabilizes pulsating readings.

Q4: What fluid can I use with this sensor?
A: Air or non-corrosive gases work well. Avoid corrosive media that attack the die-cast zinc pressure port.

Q5: Does it include an analog output?
A: Yes. The AP-31K provides 1 to 5 V analog output with a minimum load impedance of 47 kΩ.