Air Gap Sensors[DPA-SR/LR]
±0.5μm Repeatability

Not “Existence detection”,
but “Precision seating confirmation.”
The new standard for pneumatic “Gap Sensors.”
Effectively prevent CNC industrial machined defect products by detecting workpiece floating due to cutting chips.
Reasons to choose Metrol’s Air Gap Sensors

±0.5μm− Repeatability
Minimal signal point variation and effective
detection of workpiece floating due to cutting chips.
Accurate seating confirmation can be conducted within the allowable tolerance, preventing machining defects.

IP67 Protective structure
Sensor can be installed inside machine tools.
Shortened air piping improves response speed and realizes higher productivity.

One-push master setting
The signal set point can be configured by placing a master within allowable tolerance into the jig and keep pressing the master set button down for one second.
There is a self-diagnosis function.
Alarm signal is output and LED flashes when the air pressure
is outside appropriate measurement pressure range.

2 Signal Point Setting Type
Available Now!
3 classifications (-NG, OK, +NG) by setting upper and lower limit points.
Realize precision inner diameter measurement at low cost!
Machine can be automated by externally outputting measurement signal.
Case studies
Metrol VS Competitor
Metrol’s Air Gap Sensor |
Air sensors / Gap sensors made by another companies |
|
---|---|---|
Repeatability | ![]() ±0.5μm− |
![]() ±20μm− |
![]() |
||
Workpiece “Precision seating confirmation” can be realized. Minimal signal point variation and effective detection of workpiece floating due to cutting entrance. Accurate seating confirmation can be conducted within the allowable tolerance, preventing machining defects. |
Only workpirce “Existence detection” possible Large signal variation means only workpiece existence detection is possible. It is impossible to detect workpiece floating due to cutting chips and to accurately confirm workpiece and jig seating. |
|
Detection distance | ![]() 1−350μm |
![]() 40−250μm |
Protective structure | ![]() IP67 (Can be used under harsh environment where coolant splatter) |
![]() IP66 (Not suited in harsh environment) |
Response speed | ![]() About 0.8 seconds ( Tube length: 1.5m) Air piping can be shortened by installing sensor inside machine tools. |
![]() About 5 seconds (Tube length: 12m) Longer air piping is necessary because sensor shoud be installed outside machine tools |
Numeral display | ![]() No display (only ON/OFF signal)* |
![]() With display |
*The signal point can be configured by pressing the master set button.
Product list
Product No. | Detection range | Signal point setting | Download | ||||
---|---|---|---|---|---|---|---|
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DPA-SR1 |
1−100μm Short range detection type |
1 signal point setting type | Catalog (PDF) |
Manual (PDF) |
CAD (DXF) |
|
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DPA-SR2 | 2 signal point setting type 3 classifications (-NG, OK, +NG) |
Manual (PDF) |
CAD (DXF) |
|||
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DPA-LR1 |
80−350μm Long range detection type |
1 signal point setting type | Manual (PDF) |
CAD (DXF) |
||
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DPA-LR2 | 2 signal point setting type 3 classifications (-NG, OK, +NG) |
Manual (PDF) |
CAD (DXF) |
|||
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NEW!! DPA-PLR2B |
3 signal point setting type | Manual (PDF) |
CAD (DXF) |
Specification
Product No. | DPA-SR1 | DPA-SR2 | DPA-LR1 | DPA-LR2 | DPA-PLR2B |
---|---|---|---|---|---|
Detection range | 1−100μm* | 80−350μm* | |||
Repeatability | ±0.5μm:Detection range 1−60μm ±1μm :Detection range 60−100μm Air pressure change within ±1%* |
±1μm:Detection range 80−150μm ±3μm:Detection range 150−250μm ±5μm:Detection range 250−350μm Air pressure change within ±1%* |
|||
Response speed | 0.8 seconds * | ||||
Electrical response speed | 80ms | 10ms | 80ms | 10ms | |
Protective structure | IP67 | ||||
Setting pressure | 0.15−0.2MPa | ||||
Operating temperature range | 0℃−60℃(no condensation) |
*Tube length 1.5m / when using a recommended nozzle
Case studies of DENSO Corporation

Prevent machining defects with CNC machine tools using precise workpiece seating confirmation.
DENSO’s Driving Safety Production Division manufactures ABS actuator parts that are vital components for safety of automobile.
There was a trouble with defective products due to seating failures of workpieces in cutting by CNC machining center.
The biggest headache was having to stop the line for a full inspection.
Applications

Adhesion confirmation in machining the engine
±0.5µm high accuracy can realize precisely cutting and machining the engine.

Adhesion confirmation of shank
Precision machining can be realized by detecting 10µm gap caused by cutting chips.

Adhesion confirmation in machining tire molds
A 10μm uplift by the cutting chips can be detected by the improvement of the machining accuracy.

Seating confirmation of workpiece with rough surfaces
Effectively detects seating of die-casting components with 350µm detection distance.

Adhesion confirmation to mold pressed by oil pressure
A 10μm of foreign materials is stably detected in gaps between the cope and drag.
Awarded an “excellence prize” in “Tokyo venture Technology Award 2015”
One of Metrol new products won an "Excellence award" in "Tokyo venture Technology Award 2015"!"Air Micro Switch", a…
Posted by Metrol Tool Setter (for CNC Machine) on 2015年12月23日