ST VA8041 User manual

Ultrasonic Thickness Gauge
VA8041
Operation Manual

Contents
Ⅰ．Preface…………………….………………………..1
Ⅱ．Safety information…………………………………1
Ⅲ．Functions & Features………….…………………..1
Ⅳ．Specifications………………………..……..…..…2
Ⅴ．Mounting battery & probe.….………………….…3
Ⅵ．The method of usage….……………….……..…….3
Ⅶ．Calibrating Meter…….……………………………6
Ⅷ．Notices…………………………...….….……..…….7

Ⅰ．Preface
Please read the following information carefully
before using the meter. The ultrasonic thickness gauge
has been designed to measure the material thickness that
callipers can’t measure, such as boiler, pressure vessels,
armor of tank, ship hulls, glass wall, tubes and so on.
Ⅱ.Safety information According to European
Union’s CE safety norms.
Please use it according to the following condition.
Environment conditions:
●Ambient temperature: -10~ +50℃(+14~ +122℉)
●Storage and transport temperature: -40~+70℃
(-40~+158℉)
Maintenance & Save:
Do not clear the meter using alcohol and impregnate. If
you do not use it for a long time, please take out the
batteries and place the instrument in a dry surrounding.
Ⅲ．Functions & Features
●Measuring thickness of various good ultrasonic wave
conductors as steel, aluminum, copper, glass etc.
.1.

●Ultrasonic wave velocity or thickness display.
●Manual material selection.
●Ultrasonic wave velocity adjustable.
●Thickness unit “mm” or “inch” optional.
●Ultrasonic wave velocity testing.
●Coupling state display.
●Shut down manually or automatically.
●Low battery voltage indication.
●Buit-in calibration metal block (4.0mm).
●Software calibrating to insure high reliability.
Ⅳ．Specifications
●The meter has been designed according to EC directive:
89/336/EEC.
●Ultrasonic wave frequency：5MHz.
●Digital display：4 digital.
●Measurement range：1.2mm~220mm (steel).
●Tubes measurement：minimum dia. 20mm*3mm.
●Ultrasonic wave velocity：1000~9999 M/ S.
●Resolution：0.1mm.
●Accuracy： ±(1%H+0.1mm).
●Measurement rate：0.6 second.
.2.

●Power supply: 7# alkaline cell , 1.5V*3 .
●Operating temperature: -10 ~ +50℃(+14~ +122℉)
●Storage temperature：-40 ~ +70℃(-40 ~+158℉)
●Dimensions：(L)×(W)×(H) mm.
●Weight ：approx g (including battery and probe).
●Accessories：probe, coupling paste, operating manual,
batteries.
Ⅴ．Mounting battery and probe
Remove the battery cover on the back and put in three
1.5V 7＃alkaline batteries according to the mark on
the shell to insure putting batteries in correctly, then
close the battery cover. Insert two plugs of the probe
into two sockets on the top of the meter.
Ⅵ．The method of usage
1. Press button “On/Off ” , the meter selects material 1
automatically , and displays the velocity of ultrasonic
wave in material 1.
2. Press button “Select” to choose a material you will
measure. A number displays on the bottom of the screen
to indicate the material. The numbers correspond to the
.3.

materials listed in table (1). Smear a little of coupling paste
on the surface of the measured object, put the probe on
and press it. A coupling symbol would appear If coupling is
all right. Synchronously the thickness of the measured
object would display instead of ultrasonic wave velocity. If
coupling isn’t good, the coupling symbol will not appear
and can not get thickness.
Table(1)
Digit Material Ultrasonic wave speed
1Iron 5900 M/S
2Aluminum 6320 M/S
3Copper 4700 M/S
4Brass 4430 M/S
5Gold 3240 M/S
6Silver 3600 M/S
7Zinc 4170 M/S
8Stannum 3320 M/S
9Glass 5850 M/S
10 Plastic 2250 M/S
11 Toughened tile 5580 M/S
.4.

12
Water(20°C) 1480 M/S
13
Material a 6500（user adjusting）
14
Material b 5500（user adjusting）
15
Material c 4500（user adjusting）
16
Material d 3500（user adjusting）
17
Material e 2500（user adjusting）
3. When take the probe out from object, the coupling
symbol disappears, but thickness keeps displaying.
4. At the state of displaying thickness and do not measure,
Press button “mm/inch”, thickness unit “mm” changes
into “inch” or contrarily.
5. At the state of displaying thickness and do not measure,
press button “Select” to display ultrasonic wave speed,
thickness will disappear.
6. Material a~e (digit 13~17) are offered to user to set
own material. Press button ▲or ▼, its velocity is
adjustable.
7. If user do not know the ultrasonic wave velocity of
own material, can test it by oneself：
.5.

A. Make a block with measured material (the more thick
the block, the more exact the result is), measure its
thickness by a callipers carefully.
B. Select anyone of material a~e, and measure its
thickness by the probe. When the digits of thickness
display steady , take the probe out from the block.
C. Press button ▲or ▼to change the digits untill it is
equal to the value measured by the callipers.
D. Press button “Select” ,the ultrasonic wave velocity of
user’s material will appear. When shut the meter down,
the ultrasonic wave velocity will be saved into a
memory.
8. To set power off :
When the meter is working, pressing button On/Off
will get shutdown immediately.
9. Automatic shutdown
When the meter is working , and stop to press button
for five minutes, shutdown will occur automatically.
Ⅶ．Calibrating the meter
When changing a new probe, or the probe is abrased or
the meter is used for a long time, you need to calibrate
.6.

the meter by yourself, the method is follow：
Power on the meter, smear a little of coupling paste
on the surface of the metal block buit-in the shell of the
meter. Put the probe on and press it, when coupling
symbol appears, press button “Adjust” for two seconds,
four bars appear on the screen. Keep to press the probe,
button “Adjust” can release. You can see the bars
disappear gradually.Finally “4.0 mm” displays, the meter
will be calibrated.
Ⅷ．Notices
1. The ultrasonic wave velocity listed in Table(1) is for
reference. Because the component of your material may
not be identical with that listed in Table(1), had better
make sample block to test the wave velocity in it.
2. Poriferous matter, or uncompacted material isn’t a good
ultrasonic wave conductor, can not be measured by the
meter. Casting has large crystals, if its surface is rough,
it is difficult for us to test thickness by the meter.
3. When measuring thickness under 2.5mm, sometimes an
error named as “double refraction” may occur. Another
error is named as “ pulse envelope or cycle jump”. They
.7.

bring on a bigger result than actual thickness. So when
measuring thin object, should do it repeatedly to look for
the least value. If necessary, make an thin block to
compare measuring result.
4. Rough surface may affect test, Burnish it by sand paper,
and then measure.
5. When the surface has thick paint, scrape it off and then
measure.
6. Coupling paste is necessary for test, it can eject air out
off the gap between the probe and the object to get
ultrasonic wave to pass. For slippery surface as glass,
water can replace coupling paste. For rough surface,
more viscous coupling paste must be used, such as
lubricating oil.
7. To measure tubular object, Smear more coupling paste,
get the direction of sound insulation board in the
probe perpendicular to axes of the tube, rolling the
probe along the axes back and forth slowly. When the
coupling symbol appear, look for the minimum value.
For small tube (diameter =20mm), if it’s thickness is
less than 3mm, the result of measurement is wrong.
.8.