Coating Thickness Gauge Instruction manual MT4100-MT3100

1 Overview
The instrument adopts the magnetic and eddy current principle to measure in a non-destructive way .The instrument is a portable thickness-measuring meter, it can measure the thickness of coating and plating rapidly, non-destructively and precisely.It can be used both in lab and the work site.This instrument can be widely used in the inspection fields, e.g. manufacturing, metal processing, chemical industry and commodity inspection, etc.It is a gauge essential for the material protection.
The meter meets the following standards:
GB/T 4956─2003 Measuring Thickness of the Nonmagnetic Coating on a Magnetic Metallic Substrate, Magnetic
GB/T 4957─2003 Measuring Thickness of all electrically insulating coating on nonferrous metals, Eddy current Way

1.1 Measuring Principle

The instrument adopts the magnetic and eddy current principle to measure in a non-destructive way
Magnetic way (type F probe)
measure the thickness of non-magnetic coatings on magnetic metallic base (e.g. zinc, aluminum, Cr. Copper, rubber, paint, coating on the base of steel, iron, alloy and hard magnetic steel etc.)
eddy current way (type N probe)
measure all electrically insulating coating layers,such as lacquer,Varnish, paint,anodizing coating on nonferrous metals,also on austenitic VA steel materials.

1.2 Standard Configuration

                    

1.4.1 LCD Display

Type N probe ：

2 Preparations for measurement

2.1 Check Voltage

The instrument can be operated using 9V battery .
Press“ON/OFF”，Please pay attention to battery.
If the instrument is not switched on, it has no battery or lower Voltage。Please replace the battery.
No indicated by the flashing battery symbol, the instrument has plenty of voltage.
indicated by the flashing battery symbol, the instrument has a lower voltage, Please replace the battery.

2.2 Replacing the Battery
b)Open the battery box;
c)Take out the batteries and place in new ones, notice the polarity;
d)Cover the battery box.
If the instrument will not be used for long time, you shall take out the batteries, so as to prevent the instrument from corroding by the batteries.

2.3 Basic Measuring Steps
Get ready the test piece, Place the probe in an open space, press ON/OFF, turn on the instrument;
When it is normal, after start up, it will display the measurement kept when shut down last time, e.g.:

                                           

Whether it is necessary to calibrate the instrument, and if necessary calibrate it in a proper way;
Measure
Get rapidly in a vertical way the probe into contact with the test surface in a vertical way and press lightly the positioning jacket of the probe, after a buzz, it will display the measurement on the screen, raise the probe for the next measurement; If the measurement exceed the range it will display ----.
Turn off the instrument
The gauge can be turned off automatically or by hand.
Auto turning off: The instrument will turn off automatically 2~3min later if it has no operation.
Manual turning off: By pressing “ON/OFF” it will turn off immediately.

2.4 Functions and Operation Way

2.4.1 Working Way
The instrument has two working way.: direct and APPL
a)In the direct way： Max 100 latest measured values can be stored. If 100 readings are stored in the direct way ,The latest value instead of the first One.
b) In APPL way ：Max 100 measured values can be stored in any APPL.There are five APPL ,a total of max 500 readings of the five APPLS can be stored.
If 100 readings are stored in this APPL,the instrument display “full of memory. the values can be measured,but it is not stored.
Converting two working way：
When the instrument is switched on,Direct will be automatically diplayed.
a) Press“MENU”， “system setup ”appears；Press“MENU”
b) Press“↑”or“↓”，select“working”；
c) Press“MENU”， “working”setting。


Note： “*” there is calibration values in this APPL；

Press two “ESC”。

2.4.2 Measuring way
There are two measuring way：single measuring and continual measuring
Single measuring – once the probe contacts the test piece, a buzz will give out, and it will display a measurement;
Continual measuring-the probe is measuring continually,display values continually.
Converting two measuring way：
single measuring or continual measuring；
a)Press“MENU”， “System Setup”options appears；
b)Press“MENU”，select “Meas”
c) Press“MENU”，selecte “Single” or “Cont”；
d) Press two “ESC”。



2.4.3 Converting Units (Metric <=> Inch)
a)Press“MENU”， “System Setup”options appears；
b)Press“MENU”，Press“↑”or“↓”select“unit setting” ;
c)Press“MENU”，select“unit：um”or“ unit：mils”；
d)Press“ESC”。



2.4.4 Online statistical values
a) Press“MENU”， Select “System setup”；
b) Press“MENU”，Press“↑”or“↓”select“stats”setting;
c) Press“MENU”select “stats:on”or“stats:off”；
d) Press two“ESC”，ESC。



2.4.5 Limit value setting
To monitor your measured values,you can set an upper and a lower limit value.This setting is useful. If the limit value is exceeded or if it is not reached,an audio signal will sound,and a warning note will appear on the display.
a)Press“MENU”，press“↑”or“↓”，select“Limits”；
b)Press“MENU”，enter“Limits”；
c)Press“MENU”select“Upper”or“Lower”，press“↑”or“↓”until the numerical value for the upper limit value or lower limit
value is set.
e)Press two“ESC”，OK。




2.4.6 Online print（TT4100）
Online print : Connect the infrared adapter with the printer using the RS232 interface .
If the “online printout： on”,the
single values can be transferred to
a printer.

a) Press“MENU”， Select “System Setup”；
b) Press“MENU”，Press “↑”or“↓”select “Print” ；Press“MENU”select“print：on”or“ print：off”；
c) Press“ESC”，ESC。

2.4.7 Backlight setting
Press“ ”,shut on or shut off backlight.

3 Calibrating the Instrument
In order that the measurement is accurate, one shall calibrate the instrument at the measuring site

3.1 Calibrating Way
Three calibrating ways are available during the measuring for the instrument: Zeroing, Two-point calibration and a basic calibration in respect to the probe.The calibrating of the instrument is very simple.

3.1.1 One-point calibration(Zero-setting)
To do this,you have to use an uncoated test object having similar dimensions and material properties to those of the coated object.
a)Make a measuring on the substrate, it will display on screen ＜× ×µm>.
b)Press ZERO key, the screen displays <0.0>.。The calibration completes, you can now begin the measurement.
You can repeat continuously several times, so as to get the mean value for several calibrations, in this way you can improve the accuracy for calibration;

3.1.2 Two-point calibration

3.1.2.1 One calibration foil
As with, “Zero setting”,you have to use an uncoated test object having similar dimensions as the coated objectto do this. Choose a calibration foil which is closest to the expected coating layer thickness.
When measuring after this calibration,the guaranteed measuremen tolerance are complied with.
Carry out one-point calibration as described 3.3.1。
Put the calibration foil on the uncoated test object and place the probe repeatedly on the foil. Make a measuring, it will display on screen ＜× ×µm>.
Press“↑”or“↓”,until the thickness value of the calibration foil agrees with the displayed value。The calibration completes, you can now begin the measurement.
Note:If the thickness value of the calibration foil agrees with the displayed value, Press“↑”and “↓”must be set，
2. You can repeat continuously (b,c)several times, so as to get the mean value for several calibrations, in this way you can improve the accuracy for calibration;


3.1.2.2 Two-calibration foil
Choose two calibration foil which is closer to the expected coating layer thickness, the expected coating layeis thickness is between the two calibration foil value. upper value shall be at least 3× of the lower one.in this way you can improve the accuracy for calibration.
a)Carry out one-point calibration as described 3.3.1。
b)Put the lower calibration foil on the uncoated test object and place the probe on the foil. Make a measuring, it will display on screen ＜× ×µm>. Press“↑”or“↓”,until the thickness value of the calibration foil agrees with the displayed value。
c)Put the upper calibration foil on the uncoated test object and place the probe on the foil. Make a measuring, it will display on screen ＜× ×µm>. Press“↑”or“↓”,until the thickness value of the calibration foil agrees
The calibration completes, you can now begin the measurement.

3.2 Correcting the Basic Calibration
It is necessary to change the basic calibration under the following case:
- The probe tip is worn.
- Special application.
If the error exceeds obviously the given range during measuring, you shall re-calibrate the probe, this is called basic calibration.You can re-calibrate the probe by inputting 6 calibrating values (one zero and five thickness values).
With the instrument is OFF, hold down ↑, then press ON/OFF, now you enter into the basic calibrating status for type F probe;
Zero first as described 3.3.1。. You can repeat continuously several times, so as to get the mean value for several calibrations, in this way you can improve the accuracy for calibration;
Use standard pieces in thickness-incremental order, and you can calibrate several times for each thickness value. Each value shall be at least 1.6× of the previous one, and it’s best to be 2×. For example F1: 50μm, 100μm, 200μm, 400μm and 800μm.The max. value shall be close but lower than the max. measuring range of the probe.
After inputting 6 calibrating values, measure the zero point, the instrument turns off automatically, and the new calibrating value has already saved in the instrument.At a new startup, the instrument will work with the new calibrating value.

Note: 1、Each thickness shall be at least 1.6× of the previous thickness, otherwise it will be regarded that the basic calibration failed.
2、If the thickness value of the calibration foil agrees with the displayed value, Press“↑”and “↓”must be set，

4 Measurement and statistics

4.1 Memory function
In direct way,Max 100 latest measured values can be stored.
In APPL way , Max 100 measured values can be stored in any APPL.There are five APPL ,a total of max 500 readings of the five APPLS can be stored.
If 100 readings are stored in this APPL,the instrument display “full of memory. the values can be measured,but it is not stored.
4.2 Statistics
The instrument is provided with online statistics .This means that the statistics values are re-calculated and displayed in the two bottom lines after every measurement.The statistics values calculated by instrument are:
No: Number of measured values
Mean:Average of measured values
S.DEV: Standard deviation
Max: Maximum single value of the measurement series
Min: Minimum single value of the measurement series
⊙ In direct way, a total of max.100 readings can be stored. The new reading instead of the first reading.
⊙ In APPL way，the statistics values calculated during this APPL.

4.3 View
Display of measuring values andStatistical values
a)Press“MENU”，press“↑”or“↓”，select“View ”；
b)Press“MENU”，press“↑”or“↓”，select display measurments or Statistics；
c)Press“MENU”，select“Statistics”,it can be displayed :


5 Deletion function

5.1 Delection single value
In any working way，press“Clear”，delection the end measuring value.

5.2 Delection measuring values or all Values
In any working way, all measuring values are delected.
a)Press“MENU”，press“↑”or“↓”，select“Function”；
b)Press“MENU”，enter“Function”；Press“↑”or“↓”，select“delecte File”or “delecte All”；
c)Press“MENU”，display“Press[MENU] to confirm”or“Press[ESC] to cancel” Press“MENU”t, all measuring values are delected.
d)Press two“ESC”，OK。

6 Printer（TT4100）

6.1 Preparations for Print
The infrared data transmission from instrument to a printer；
The infrared adapter must be connected to the printer.
Press“ON/OFF”；
The printer must be set as follows:
-Baud rate: 9600、
_Data bits: 8
-stop bit: 1

6.2 Print function
a) Press“MENU”，Press“↑”or“↓”，select“Function”；
b) Press“MENU”，Press“↑”or“↓”，select “Print File ” 、 “Print Stats” 、“Print all”，Press“MENU”。
c) Press two“ESC”，OK。

7 Data transfer to PC using（TT4100）
The serial interface parameter of the PC must be set as follows:
-Baud rate: 9600、
_Data bits: 8
-stop bit: 1
a) Press“MENU”，Press“↑” or“↓”，select“Function”；
b) Press“MENU”，enter“Function” press“↑”or“↓”，select “Send Date”
c) Press“MENU”，in direct way，sentStatistical values and single values；In APPL way, sent statistical values and single values in this APPL；
d) Press two“ESC”, OK。

8Factors Influencing the Measuring Accuracy

8.1 Description about the Influencing Factors
a) Magnetism of substrate metal
The thickness-measuring in magnetic way will be influenced by the magnetism change in metal (in practice, the magnetism change in mild steel can be taken as slight), in order to avoid the influence from heat treatment and cold machining, you shall calibrate the instrument by using standard pieces with the same characteristic with the test substrate metal; or you can calibrate the instrument with the test piece that is to be coated.
b) Thickness of substrate metal
Each instrument has a critical thickness of substrate metal.When being higher than this thickness, the measuring will not be influenced by the thickness of substrate metal.As for the critical thickness of this instrument, please refer to attachment table 1.
c) Edge effect
This instrument is sensitive to the sudden change in surface shape of test piece.Therefore the measurement near the test piece’s edge or inner corner is not reliable.
d) Curvature
The curvature of a test piece will influence the measuring.This influence will always increase as the curvature radius reduces.Therefore, it is not reliable to measure on the surface of a curved test piece.
e) Deformation in the test piece
The probe will make the soft coating deform, therefore it is impossible to get reliable data on such kind of test piece.
f) Surface roughness
The surface roughness of the substrate metal and coating will influence the measuring.The higher the roughness is, the higher its influence will be.A rough surface will result in systematic error and accidental error. During each measurement, you should increase the measuring times at different positions so as to avoid such kind of accidental error. If the substrate metal is rough, you have to zero the instrument by several positions on the test substrate metal that is not coated and with similar roughness; or you can zero the instrument by removing the coating by solving it with a solution that will not corrode the substrate metal.
g) Magnetic field
The strong magnetic field generated by different electric devices surrounding will seriously disturb the thickness measuring in magnetic way.
h) Substance attached
This instrument is sensitive to the substance attached that will hinder the close contacting between the probe and coating, therefore you must remove the substance attached so that the probe can contact the test surface directly.
i) Pressure of probe
The pressure applied by the probe on the test piece will influence the readout of the measurement, therefore you must keep constant pressure.
j) Direction of probe
The placing way of probe will influence the measuring.During the measuring, you shall maintain the probe to be vertical to the test piece surface.

8.2 Matters shall follow when using the Instrument
a) Characteristics of substrate metal
For magnetic way, the magnetism and surface roughness of the substrate metal of the standard piece shall be similar with that of the test piece.
b) Thickness of substrate metal
Whether the thickness of substrate metal exceeds the critical thickness, if not, you can calibrate it by one of ways in 3.
c) Edge effect
You shall not measure thickness by placing the probe close to the suddenly changing point, e.g. edge, hole and internal corner, etc.
d) Curvature
Never measure on the curved surface of the test piece.
e) Times for reading readout
Normally, as the readouts of the instrument are not completely the same, therefore it is necessary to take several readouts in each measuring area.For the local difference in coating’s thickness, it is also required to make several measurements in a given area, especially the surface is rough.
f) Surface cleanness
Before measuring, you shall remove any substance attached to the surface, e.g. dust, oil and corrosion product, etc., but don’t remove any coating.

9 Maintenance and Repairing

9.1 Requirement on Environment
Avoid impact, heavy dust, damp, strong magnetic field and greasy dirt, etc.

9.2 Error display
1) Probe is too close to metal:
The probe was too close to the metal during switch-on. Hold the probe free in the air and then switch the instrument on.
2) Magnetic interference fields
Close to the probe are too strong magnetic interference fields
3) Instrument defective
If this error message appears,please send the instrument to your supplier or to the manufacturer for repair.
4) Other errors
If the following errors appear on your instrument :
Instrument does not allow any further measurements；
not logical display values；
Keys have no more function；
Please remove the battery within 20 seconds. Insert the battery again and reset the instrument.

9.3 Total Reset
This setting causes:
a)the delection of all single values and of the statistical values
b)the delection of the set calibration values and resetting to all calibration
Procedure:
a.Switch off the instrument ，Press“ZERO”and“ON/OFF”，untill appears“reset？”；
b.Press“MENU”，Display“reset”set reset；

10Matters Need For Attention
I. After purchasing product from our company, please fill carefully the Warranty Registration Card and stamp your office on it. Please send copy (I) and the copy of invoice to the User Service Dep. of our company, or you can ask the seller to send that on your behalf.(II) The copy (I) will be sent to (left at) the maintenance station of local branch for registration.For any area without maintenance station, please send copy (I) and (II) back to the User Service Dep. of our company.When the procedure are not complete, we can only maintain but offer no warranty service.
II. For any product from our company, since the day user purchases it, if it has any fault in term of quality (except for non-warranty parts), please contact the maintenance stations of local branches at different areas of our company for repairing, replacing or returning by using the “Warranty Card” (the copy kept by the user himself) or the copy of the invoice issued when purchasing the product.During the warranty period, if one has no way to show the warranty card or the copy of the invoice, we will count the warranty period based on the shipping date, and the period is one year.
III. If any product of our company has fault after the warranty period, the maintenance will be charged according to prescription of our company.
The “special configuration” beyond our established product will be charged according to concerned criteria.
V. Our company will not warranty any product which is damaged because the user has disassembled by himself, due to improper transportation and storage or incorrect operation not following the “Operation Instructions”, as well as for which one has altered the Warranty Card and one has no Purchasing Proo