Original of Products : JAPAN







Principle of Air Micrometer



What is Air micrometer?

Relative measuring instruments which can measure dimensions of various workpices like machine parts by using air flow is called Air Micrometer. 
It comes in Flow type and Back Pressure type mainly.

Here we explain flow type-as illustrated in the above fig. The compressed air from compressor is cleand by a filter, and then into a regulator
to keep the pressure  constantly. 
After that, the air goes through taper tube, and blows up of a nozzle. Next, when the clearance between
the nozzle part and the workpiece changes, the amount of air coming out of the nozzle also chenges, causing the height of a float to change.
By reading the graduated positions of the float, the actual dimensions of the workpieces can be determined. This is the princible.

ISSOKU’S  Air Micrometer is supported by our many years of precision gauge manufacturing techniques, and it is of highly appraised for its reliability and precision,
making it of great value in quality control and
increased efficiency in a world-wide industrial world.

ISSOKU’S AM’s four basic models- the Column Model(flow type), dial model(back pressure type), Digital Model(back pressure type) - can be used not only
to measure dimensions, but also for complicated profile measuring automatic measuring, automatic sorting and etc., making them practical over a wide variety of uses.
The measuring head can be standardized according to measuring factors and also by order-made designs to meet various measuring requirement.


Main advantages of the Air micrometer

1. Measured by air blow, an accurate measured value can be obtained with out being affected by oil or dusts.
2. Basically, as a result of non-contact measurement, the workpiece to be measured is not corrupted.
3. With high quality and supperior stability, it is easy to operate.
4. Many kinds of measuring heads are available, for a wide range of measuring purposes.
5. A unique taper tube keeps the float from sticking to the upper area. Furthermore it is easy ti remove and fabricate (column type).
6. Because of "block-built method" (column type), it can easily be set up to measure multiple places.
7. The back pressure type has superior stability of measured value in measurement against change of air pressure.
8. In addition to the basic functions, other automatic measuring functions such as class sorting and data output are installed.


Measurement example of Air micrometer

Measurement as below can be applied by using various measuring heads.

For Thickness
For Internal dia. (Through hole)
For Internal dia. (blind hole)
For Internal dia. (Ball contact type)
For internal dial. (Plate spring type)
For external dia. (Ring type)
For external dia. (Caliper type)
For Thickness
For straightness
For mating between bore and shaft
For conicity of inner cone
For perpendicularity
For spacing between separate cylindrical bores
For spacing between separate cylindrical bores (special purpose)
For conicity, form & basic diam.
For multi-Places
Column Model Air Micrometer flowmec (PAT.)

Column Model Air Micrometer flowmec (PAT.)

Flowmec is a precision relative measuring instrument that measures changes
in airflow running through a slight clearance between workpiece and
head as read by the expansion of a float in taper tude.

The measuring system consists of flowmec main body(a filter unit and touch
tube are standard accessories), measuning head and masters.



  1. Superior stability. (Less than 2% active reading range)
  2. Two standard magnifications can be shared.
    (The body with the black float shares magnifications
    of 2,000 and 5,000 times.)
  3. Since the upper damper is made of resin, it won't scratch the float.
  4. The maguification setting and zero adjusting knobs and located
    separately, making operation easy.
  5. Taper tubes are easy to remove.
  6. Magnification standards of all taper tubes are the same.
    (in cases of changing magnification, change the float and scale board)
  7. Can be fabricated to compact multiple columns by adding basic unit
    between feet.

How to fabricate multiple columns

When performing multiple places measurements, flowmec can be easily fabricated to multiple columns be adding to
basic units of NO.3100 required and right & left feet.

The above picture shows a three colums flowmec with a measuring head and master for taper degree measurement.

Number of
No.3101Single column1043.8
No.3102Double columns1386.0
No.3103Three columns1728.2
No.3104Four columns20610.4
No.3105Five columns24012.6

Indication of number of columns and magnitication is required when placing an order.
Ex) No.3103(there columns)X5000

Part Names and Dimensions

  1. Column flame
  2. Magnification setting knob
  3. Zero adjustment knob
  4. Screw for secure the scale plate
  5. Taper (glass) tube
  6. Scale board
  7. Float
  8. limitation indicator
  9. lower damper
  10. Upper damper
  11. Taperred tube seal (Upper and lower)
  12. Head cover
  13. Tapered tube holder
  14. Regulator
  15. Ball valve (Ø8mm. with touch joint)
  16. Measuring head joint (M10x0.75)
  17. Foot (right)
  18. Foot (left)
Note: Please contact us if you would like to change the number of colums adter purchasing this Product. 


Standard MagnificationstimesX10000X5000X2000X1000
Measuring rangeµm2040100200
Effective measuring rangeµm153070150
Scale Volumeµm0.5125
Scale widthmm5545
Float color
Max. Measuring errorµmLess than 2% of effective measuring range4
Response timesec.Within 1.5 (value according to conditions specifled in JIS B7535)
Tolerance marker
Measuringnt head connecting screw M10x0.75 male
Air pressure suppliedkPa245 ~ 785
Basic unit sizemm34(W) x 477(H) x 192(D)
Single column unit sizemm104(W) x 479(H) x 192(D)
Basic unit weightkg2.2
Single column unit weightkg3.8
Note: The upper damper is exclusively for the specifications of the standard x 1000 magnification.


Standard Accessories

• Filter unit (Including a mist separator, ODØ8 touch joint for outlet)
• Touch tube, 2m length (for use in cut off valve amd filter unit connection)

Digital Model Air Micrometer mini

Digital Model Air Micrometer mini [DI-10]

Compact type pursuing user’s measurement intentions and needs.
Each size of W67mm x H107mm(124mm for DI-40)x115mm.
has a built-in regulator and complies with multi power supplies
within a range of 85 to 264V for multiple area usage.
Basic model is called DI-10 but other models with
additionalfunctions(DI-20,21,40) are also availavle.
Select each model dependent on intended usage.

Previously the air pressure of flow type air circuits was limited due to the use of tapered glass tubes.
Now through the use of a backpressure type circuit, higher reliability of the measuring. head and furthermore, eliminating oil or dust of measuring workpices.

Moreover, since it is a differential pressure type comprising of a parallel bridge circuit trough the addition of a zero adjustment circuit(colored red) to the back 
pressure type air circuit, it is less influenced by pressure fluctuations in air supply, which can result in higher sensitivity and a wider range of measurement.



  • Adjusting knobs is applied for easy operation.
  • Superior admission decision function has three kinds of indications like O.K, +NG, and -NG.(DI-20,21,40)
    Each measured value is indicated in three colors of green (OK), red(+NG), yellow (-NG), thus decision output reading is also superior (DI-21).
  • Controleed input/output function is available to measurement of TIR or MAX/MIN. (DI-21)
  • RS485 data output function can make max.31 units of mini connect with one personal computor. (DI21)
  • Analog display can help to read MAC/MIN value and position in the tolerance easily.
Dial type air micrometer DI-300

Mist separator and base unit are option.


Analogmeter with high visibility applied,
thus workshop load reduced by easy read.

DI-300 can realize high sensible and stable measurement applying differerntial
pressure type which has almost no influence by change of air source supplied.



  • Big scale board with analog indicator is easy to read and makes worker's tired feeling reduce.
  • This instrument applies differential pressure type.
    This method gives stable measurement because it has almost no influence by change of air pressure supplied accordingly.
  • Differential pressure type Air micrometer has higher measuring air pressure than that of Flow type Air micrometer,
    thus more wide measuring clearance gives high durability of measuring head.
  • Polarity inversion for internal or external measurement is easy to operate by switching oone lever.
  • Easy to operate set-up of maginification adjustment and zero adjustment because each nob is independent.
  • Full magnification series can meet your mesuring requirement.
    Extra-small diam. nozzle like 0.3 nozzle is one of environment cinscious products to realize energy saving.

*As to "differential pressure type", please refer to catalog of Digital Model Airmicrometer "mni".

Column Model Air Electronic Micrometer COLMEC® (PAT.)

Column Model (BAR-GRAPH TYPE) Air/Electronic Micrometer COLMEC® (PAT.)


The Column Model(bar graph type) Air Micrometer and Electronic Micrometer ”COLMEC” is easy to use in production areas or inspection rooms. 
Two specifications, the Air Micrometer and Electronic Micrometer, make various measurement possible.

In addition to the dimensions, profile, position, and runout of the workpiece can be measured by multi-column combination can be quickly and accurately.
A single chip microcomputer provides this product with outstanding cost performance. All models come equipped with RS-485 output,
so data can be 
transmitted to a computer or parameters set-up can be operated via a computer, thorugh the interface.

They are also shipped with ranking assessment output, extermally-controlled input and analog input for temperatre correction,
enabling them to handle many factory 
automation requirements such as automatic measurements.

Air Micrometer
A1 is air micrometer (back pressure type) with high accuracy and multiple function.
This type is suitable to regular measurementsof internal/external diam., thickness,etc.
A1D has same function as A1, but this is suitable to differential measurements
of difference of 2 places, such as taper degree, difference in incline, parallelism,etc.

  • Measuring range is changed easily by changing installed pilot jet.
  • Measuring heads can be designed and manufactured according to
    dimension/tolerance of workpiece.
Electronic Micrometer
E1 is 1CH Electronic micrometer.
E2 is 2CH Electromic micrometer which can be connected with two sensors.
It is possible to do vatious measurements by method of electrocal computing.
  • There is no switching of the measuring range.
  • E1/E2 is adaptable to our standard sensors, and the differetial transformer
    (LVDT) is adaptable to all sensors made by other companies.


  • Operation is simple since master settings
    can be configured
    via the operating keys.
  • Pass/Fail assessments can be easily made
    the three-color LED bar graph.
  • The A1 comes standard with six basic operational modes,
    while the A2 comes standard with thirty-five basic operational modes.
  • Magnification and zero position can be adjusted with a single
    touch of the operating keys.
  • All models are shipped with a conttrol input connector,
    a control output connector, and a trminal block that enable
    ranking assessments to be output and control signals to be input.
  • All models are shipped with a digital display function
    (operating mode or value of measurements).
  • Accommodates memory capture measurements and continuous
    capturemeasurements in addition to regular measurements.
  • Compact and lightweight.
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