6.4 Arithmatic Mean of Hardness of Current Measurements 13
6.5 Shutting off the PHT-2500 13
6.6 Additional Features 14
6.7 Trouble Shooting 14
7. MAINTENANCE AND REPAIR 14
7.1 Impact Device 14
7.2 Repair 14
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Figure 2: Type D Impact Device
2. Functions of the Phase II PHT-2500 Hardness Tester
Phase II PHT-2500 is an advanced, handheld hardness tester that provides high
accuracy and simplicity of operation for a wide measuring range. It is suitable
for testing the hardness of ordinary metals and is widely applied in many
industries including the petroleum, chemical, industrial machining and electric
power industries, etc.
2.1 Typical Applications
Typical hardness testing applications of the PHT-2500 include:
•Inspection of installed machinery, permanent parts of assembled systems and
heavy workpieces
• Inspection of the moulding surface of a die
• Analysis of pressure vessels, turbo generator sets, etc.
• Inspection of bearing and other mass produced parts on a production line
• Obtaining original records of test data
• Identification of metallic materials stored in a warehouse
• Quick entry of a series of test numbers, test dates, sample material type and
impact direction via the keypad.
• Deletion of erroneous or incorrect previously stored test data.
• Display of the current test mode and its corresponding test data.
• Quick print out of all test results via an optional mini-printer
• User selectable display of test data in any hardness value (
HL, HRC, HRB, HB,
HV, HSD)
•
Low Battery Indicator
2.4 Measuring and Converting Ranges
Shown in Tables 1-7 are the impact devices, the corresponding measuring ranges for
each (D, DC, DL, D+15, C, G) and their allowable conversion ranges in terms of other
static hardness values (
HRC, HRB, HB, HV, HSD
) for different metals.
Probe Application
D
DC
D+15
C
G
DL
Universal standard unit. Will handle the majority of hardness testing
applications. Weight: 75g
Very short impact device for those confined areas, i.e. inside bores for internal
measurements. Conforms to the D measuring range.
Very narrow contact area with a set backed measurement coil. This device is
used to measure hardness in grooves and recessed surfaces.
A reduced impact energy impact device
for measuring the hardness of surface hardened components, coatings, thin
wall or impact sensitive components. Applies a small superficial indentation.
Weight
This device has an enlarged test tip, and an increased impact energy range
(approx. 9 times the D, 72 ft-lb.). Can be used on lower quality finishes for
measuring hardness in the Brinell range only (max. 650 HB). Designed to be
used with heavy components such as heavy castings and forgings.
Weight
This model features a needle front section with a diameter of 4mm and a
length of 50mm. It is suitable for testing in extremely confined spaces, the
base of grooves and of special components such as gear wheels.
For use on steel and cast steel only!
: 75g (will not function at –180 degrees)
: 250g
(approximately ¼ of the D Type 2 ft-lb.)
Weight
: 50g
Weight
: 80g
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DL Impact Probe
Figure 3: Optional Impact Devices
Table 2: Impact Device – D, DC Measuring Range LD:200-900
Table 3: Impact Device – D+15, Measuring Range LD+15: 300-900
Material HRC HRB HB HV HSD
Steel & Cast St. 19.3-67.9 80-638 80-937 33.3-99.3
Table 4: Impact Device – C, Measuring Range LC: 350-950
Material HRC HRB HB HV HSD
Steel & Cast St. 20.0-69.5 80-683 80-996 31.9-99.6
Table 5: Impact Device – G, Measuring Range LG: 300-750
Material HRC HRB HB HV HSD
Steel & Cast St. 47.7-99.9 90-646
Gray Cast Iron 92-326
Nodular Cast Iron 127-364
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3. Leeb Measuring Method
3.1 History
The Leeb measuring method was first brought into measurement technology in 1978.
It is defined as the quotient of an impact body’s rebound velocity over its impact
velocity, multiplied by 1000. Harder materials produce a higher rebound velocity than
softer materials. For a specific group of material (e.g. steel, aluminum. etc.). Leeb
hardness value represents a direct relationship to its hardness properties. For ordinary
metal, conversion curves of hardness HL versus other standard static hardness (HB, HV,
HRC, etc.) are available, enabling you to convert HL into other hardness values.
3.2 Leeb Hardness Test (definition)
An impact body with a spherical test tip made of tungsten carbide is propelled against
the sample surface by a spring force and then rebounds back. At a distance of 1mm
from the sample surface, the impact and rebound velocity of the impact body are
measured by the following method: A permanent magnet embedded in the impact
body, when passing through the coil in its coil holder, induces in the coil an electric
voltage proportional to the velocities of the magnet. Leeb hardness is expressed by the
following formula:
HL = 1000 x (VB/VA)
Where: HL is Leeb Hardness
V
V
The voltage characteristic of output signal, when the impact body passes through the
induction coil is illustrated in the following figure:
is the rebound velocity of the impact body
B
is the impact velocity of the impact body
A
3.2 Leeb’s Hardness Tester (definition)
A Leeb’s Hardness Tester measures the hardness of sample material in terms of
Hardness Leeb (HL), which can be converted into other Hardness units (Rockwell B and
C, Vicker, Brinell and Shore D).
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3.3 Notation of Leeb’s Hardness
•When measuring the hardness of a sample material using the traditional static
hardness testing method, a change of applied pressure will result in a change in
the hardness reading. This will also happen during a Leeb’s Hardness test when
you change the impact device. In measuring the hardness of the same test
sample with different impact devices, the Leeb’s hardness values obtained will
vary.
For Example: 720 HLD≠720 HLC
•Because different converting curves are obtained from different impact devices,
when converting hardness L into another hardness value the notation for the
converted hardness value should include the impact device used.
For example:
Hardness HV converted from hardness L using impact device D+15
Should be written as 22, 8 HV LD+15
Where: 22=hardness value HL
8=hardness value HV
L=Leeb’s Method
LD+15-impact device
Hardness HRC converted from hardness L using impact device D should be
written as 35, 9 HRCLD
Where: 35=hardness value HL
9=hardness value HRC
L=Leeb’s Method
D=Impact device
4. Pretreatment of Samples
4.1 Pretreatment of Sample Surface
To eliminate hardness errors resulting from the roughness of a sample’s surface when
using impact device D, DC or D+15, the test surface should be polished until its
roughness Ra is no more then 2µm. PHASE II SRG-1000 handheld surface roughness
tester or any other suitable instrument may be used to measure the surface roughness
of the sample material. The test surface should be clean and free from oil stains.
4.2 Curved Surface
When testing a curved surface with a radius of curvature R less than 1.2 in (30mm), a
special small support ring washer should be used to compensate the curvature.
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4.3 Supporting a Test Sample
When using impact devices D, DC or D+15 (Impact energy=9ft/lbs), please refer to the
following support requirements:
• For test samples weighing over 11 lbs. (5 kg), no support is required.
• Samples having a cantilever or thin shell shape and weighing between 4.4 to 11
lbs. (2 to 5 kg) must be firmly coupled to bearing supports weighing over 11 lbs.
(5 kg) in order to prevent bending, deformation or displacement due to the
impact force.
•Test samples weighing less than 4.4 lbs. (2 kg) should be firmly coupled to a
support weighing over 11 lbs. (5 kg).
• The coupling surface between the sample and the support should be smooth.
• A moderate, non-excessive amount of coupling paste should be applied between
the coupling surfaces when testing thin cross section pieces with larger massed
support plates.
• The direction of impact should be perpendicular to the coupled surface.
• Minimum weight of a test sample should be 0.2 lbs. (100 g).
• Minimum thickness of a test sample should be 0.2 in (5 mm).
• Minimum depth of hardened layer should be 0.03 in (0.8 mm).
• The testing surface of the sample should be perpendicular to the impact
direction.
Note: The above restrictions referring to the rigidity of test samples can be decreased
when Type C (2ft/lbs) impact device is used as should be increased when Type G (72
ft/lbs.) is used.
4.4 Large Test Samples
When the test sample is a large plate, long bar or bent work piece, the impact force
can cause a deformation or instability when the impact device is released. This may
bring about an error in measurement, even if the weight or thickness of the test sample
seems applicable. In this case, a reinforcement should be attached to the back of the
sample surface opposite to the impact force.
4.5 Test Sample Properties
Requirements for a sample’s weight thickness and roughness differ for each impact
device, as shown in Table 8.
Table 8: Sample Requirements for Hardness Testers
Sample
Impact
Device
D, DC,
D+15
G
C
Sample Weight(kg) Min. Thickness
(mm)
Needs
Support
Needs to
be
stabilized
No
strength-
eing
needed
Sample
Hardened
layer
ISO Ra Rz
0.05-2 2.5 >5 3 0.8 N7
0.5-5 5-15 >15 10 N
0.02-
0.05
0.5-
1.5
>1.5 1 0.2 N
9
5
Max. Roughness
(or Min. Fineness)
2µ 10µ∇6
7µ 30µ∇4
0.4µ 2.5µ ∇8
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5. Keypad Functions
Shown in Fig 6 are the keypad function buttons.
Top left button Scroll up (Back light)
Top right button Delete last test
Middle left button Scroll down
Middle right button Memory recall
Bottom left button Power on/off
Bottom right button Menu display/Save entry button
6. Operation of the Instrument
6.1 Starting
Insert the plug of the impact device into the processor and switch on the power
The LCD will display the same settings that were previously set. If the display meets
your current testing requirements, you can start the test immediately. If not, you can
enter your required settings using the keypad.
6.2 Setting of all Parameters
•
Choosing an Impact Device
.
Press the button to go to the main menu. Use the button to scroll down to:
2. Impact Device. Press the
to scroll across to the desired impact device. When the desired device is highlighted,
you must press the
button to save entry.
button to enter this parameter. Press the button
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•
Setting your Impact Direction
While in the main menu, use the button to scroll down to: 3. Direction. Press the
button to enter this parameter. Use the button to move the cursor until you
reach the desired direction. Press the
button to save this entry.
Figure 7: Impact Direction
•
Obtaining an Average
While in the main menu, use the button to scroll down to: 4. Average Times.
Press the button to enter this parameter. Use the button to change the
test/average times from 2 times to 8 times. Press the button to save entry. This
function allows you to view the average of the amount of tests you entered.
Example
: If you chose “3”. The tester will show the average after 3 consecutive tests.
All test results will be shown on the display.
•
While in the main menu, press the button to scroll down to: 5. Material. Press the
Selecting a Material
button to enter this parameter. Use the button to scroll down the list until the
desired material is reached. Press the button to save entry.
•
Choosing a hardness Scale
While in the main menu, press the button to scroll down to: 6. Scale. Press the
button to enter this parameter. Use the buttons to scroll across the 6
choices of hardness scales. When the desired scale has been highlighted, you should
press the button to save this entry.
•
Setting Limitations
While in the main menu, use the
button to enter this parameter. Using the button to change the numbers and the
(upper & lower)
button to scroll down to: 7. Tolerance. Press the
button to change columns, you can enter your desired upper and lower limitations.
What this parameter allows the tester to do is signal you when a particular test has
fallen outside the set limitations. The LCD display will read as follows:
over range-repeat
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•
Entering Date & Time
While in the main menu, use the button to scroll down to: 8. Date and Time.
Press the button to enter this parameter. Use the button to change the
numerical values. Use the button to move to the next column. When your entry has
been completed, press the button to save your entry.
•
Setting Memory Locations
While in the main menu, use the button to scroll down to: 9. Location. Press the
button to enter this parameter. Use the button to change the numerical value.
Use the button to move to the next column. When your entry has been completed,
press the button to save this entry.
•
Memory Recall
While in the main test screen, press the button to recall stored data
IMPORTANT: this feature allows the user to keep track of previous measured values for future references
or printing purposes. Always keep note of your selections to quicken the process of finding your desired
measurement.
•
Error Modify
(deletions)
When an error occurs in your test grouping, you can push the button to delete the
previous test result. This will only allow one deletion per test
Example:
If you take 3 tests and the second test result is
erroneous, you can push the *button to delete that last test. You
will not be able to immediately change the first test.
Memory Function
•
While in the main menu, use the button to scroll down to: 10. Memory. Press the
to enter this parameter.
1) Auto Store:
This function will allow the user to automatically store each test result in the next available memory
location by ascending order.
2) Close store:
This function will allow the user to perform tests without any results being saved in memory. If memory
or printing functions are not needed, then this is the parameter that should be set.
When the desired memory function is set, press the
to save this entry.
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Printing stored Data using a PC or optional mini-printer
Optional Mini-printer:
Connect the included power supply in the back end of the printer. Using the supplied
data port connections, connect the single port end into the side of the PHT-2500.
Connect the 9-pin female end to the included dual male end adapter. Connect the 25pin adapter male end to the 25-pin female end data port of the mini-printer.
Follow instructions below.
Printing to a PC:
All instructions are the same as the mini-printer except you must connect the 25-pin
male end to the printer port of your PC. The desired program needed to run this
operation should be left to the discretion of the end user.
•
Printing stored Data
While in the main menu, press the button to scroll down to: 11: PRINT. Press the
to enter this parameter. The display will show a starting location and an end
location. Using the button, you can change the numerical value to the desired
memory location needed to print. Press the button to change columns. Using this
method. Enter the memory location of the first test result needed
(starting location
(
end location
) and then enter the memory location of the last test result
)needed to print.
Example:
If you chose memory location 0150 to start a set of 10 tests,
this would mean that you have stored your last test result in
memory location 0160. In order to print these test results, you
must enter 0150 as your start location and 0160 as your end
location.
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Begin Testing:
While in the main menu, use the to go to: 1. Measurement. Press the to enter
the main testing screen. Begin Testing.
6.3 Measuring Procedure
Use standard test block to check your hardness tester prior to a hardness test.
(1) Loading
Press down the loading tube to lock the impact body. (Fig 9)
Figure 9: Loading the PHT-2500
(2) Placement
Place the support ring on the surface to be measured. The distance between two test
points should not be less than 0.1 in (3mm) (Fig 10).
Figure 10: Placement of Tester
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(3) Starting
Trigger the release button while the work piece, the impact device and the impact body
are all stable and the starting force coincides with the axis of the impact device (Fig.
11).
Figure 11: Starting a Measurement
When one measurement of a set is finished, the hardness value measured will be
displayed on the LCD screen and the number of measurement times will increase by
one.
If the test data lies outside of the conversion range it will be displayed as:
over range repeat
on the LCD screen and will then be nullified.
6.4 Arithmatic Mean of Hardness of Current Measurements
Usually the arithmatic mean of measurements should be the average of 5 to 33 or more
sets of measured data.
6.5 Shutting off the PHT-2500
Press the Red power button to terminate use of thePHT-2500.
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6.6 Additional Features
•Set time and date and serial number of the test can be modified during a
measuring procedure, as necessary.
•Alteration of parameters including hardness value and type of sample material
can be performed during any measurement set. The output results of the
measurement set will conform to the newly modified setting. All the displayed
results from the current test set will follow the newly set parameters, except for
the impact direction.
•The setting of the impact direction can be changed at any time during a testing
procedure. However, only the input data after the change will be processed
according to the new setting. Data from the set impact direction before the
change will remain unchanged.
6.7 Trouble Shooting
•If the LDC screen continuously blinks, this may suggest a low battery voltage.
Simply turn off the power and change the batteries.
7. Maintenance and Repair
Avoid placing the PHT-2500 near locations where it can be exposed to shock, heavy
dust, dampness, strong magnetic fields and oil stains.
7.1 Impact Device
•Using the included brush, clean the guide tube and impact body after it has
performed 1000-2000 tests using the following procedure:
Screw off the support ring and take out the impact body.
Clean the tube by winding the brush counter-clockwise into the tube until it
reaches the bottom and then pull it out. Repeat this procedure 5-6 times.
Replace the impact body and support ring.
Release the impact spring after each test.
Never apply lubrication of any kind to impact body!
7.2 Repair
•When the tester is calibrated against the Rockwell standard test block and issues
a reading over 1 HRC, it
and should be replaced.
•Upon coming across any functional problems not mentioned in this manual,
contact a Phase II Customer Service Representative at (201)933-6300.
•
• If the unit is opened, its warranty will automatically become void.
DO NOT open the PHT-2500 or dismount any of its fixed parts. This
precision instrument should only be serviced by a factory trained service
representative.
Thank you for choosing
as your supplier of quality measuring tools
could
mean the spherical ball of the tester is worn out
14
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Revised operational instructions for the DL impact probe
If you purchased your PHT-2500 hardness tester prior to ordering your optional DL impact probe,
you must follow the instructions below before performing any tests. Without these instructions, the
outcome of hardness values will display higher than the actual hardness value of the sample test
piece.
Due to the special shape and design of the optional DL impact probe, the outcome of hardness values will
vary when compared to that of the standard D impact probe. The hardness scale for the DL impact probe
is known as HLDL. This change is how the gage can compensate for the longer impact tube. When using
the standard D impact probe, you use the HLD scale for hardness. Typically, this is the hardness scale
shown on all supplied test blocks. The HLD value will range from 750-830 Leeb. If you had purchased the
optional DL impact probe with the gage, you should have the HLDL value already shown on the test block.
If not, you need to follow the directions below.
Equation
Example: HLD 785 = HLDL 905 (785 + 120 =905)
By following this equation, you can then calibrate the hardness tester to the supplied test block by using
you new HLDL value. Once the gage has been calibrated, you can begin testing at your convenience.
The following instructions are recommended for calibrating the PHT-2500 hardness tester.
Make sure the gage is reading correctly with the standard D probe. If the reading is within +/- 1 HRC or +/- 8HLD, you are
within acceptable tolerance. Perform a minimum of 5 consecutive tests to get an accurate average. It is always
recommended to perform between 5 and 30 consecutive tests to provide you with the closest possible average.
If you need further assistance, please contact Phase II customer service at (201)933-6300
: HLD + 120 = HLDL
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Page 17
ASTM Hardness
Round Correction Factors
Corrections to be added to test results in the following scales for various diameter parts
Corrections to be added to Rockwell C, A, and D values
Hardness Diameter of Convex Cylindrical Surfaces
Reading 1/4 inc 3/8 in 1/2 in 5/8 in 3/4 in 7/8 in 1 in 1-1/4 in 1-1/2 in
6.4 mm 10 mm 13 mm 16 mm 19 mm 22 mm 25 mm 32 mm 38 mm
When testing cylindrical specimens, the accuracy of the test will be seriously affected by alignment of elevating screw, Veeanvil, indenters, surface finish, and the straightness of the cylinder. These corrections are approximate only and represent the
averages, to the nearest 0.5. Rockwell and Rockwell superficial numbers, of numerous actual observations.
The above tables are from ASTM E 18
Reprinted from the Annual Book of STM Standards, copyright American Society for Testing and Materials.
100 Harbor Drive, West Conshohocken , PA 19428-2959
3
Page 18
ASTM Hardness Conversion Chart
Rockwell C Hardness Range
Approximate Hardness Conversion Numbers for Non-Austenitic Steels, According to ASTM E-140
The Conversion Values contained herein should be considered approximate only and may be inaccurate for specific
Hardness values in Brackets are outside the range recommended for Brinell testing in ASTM E-10.
The above tables is from ASTM E-110 except values for E-scale and Tensile Strength which are not from or according to
ASTM Standards.
Reprinted from the Annual Book of ASTM Standards,
Copyright American Society for Testing and Materials, 100 Barr Harbor Drive,West Conshohocken,PA 19428-2959.
4
Page 19
ASTM Hardness Conversion Chart
Rockwell B Hardness Range
Approximate Hardness Conversion Numbers for Non-Austenitic Steels, according to ASTM E-140
The conversion values contained herein should be considered approximate only and may be inaccurate for
Hardness values in brackets are outside the range recommended for Brinell testing in ASTM E-10.
The above table is from ASTM E-110 except values for E-scale and Tensile Strength which are not from or according to ASTM
Standards.
Reprinted from the Annual Book of ASTM Standards, copyright American Society for Testing and Materials.
100 Barr Harbor Drive, West Conshohocken, PA 19428-2959
6
Page 21
ASTM Hardness
Minimum Thickness Requirements
Minimum allowable thickness for a corresponding hardness in the respective scales
Minimum Minimum - Rockwell - - - Superficial Rockwell - thickness thickness C A B 15N 30N 45N 15T 30T 45T
in. mm
0.006 0.15 92
0.008 0.20 90
0.010 0.25 88 91
0.012 0.30 83 82 77 86
0.014 0.36 76 78.5 74 81 80
0.016 0.41 86 68 74 72 75 72 71
0.018 0.46 84 66 68 68 64 62
0.020 0.51 82 57 63 55 53
0.022 0.56 69 79 47 58 45 43
0.024 0.61 67 76 94 51 34 31
0.026 0.66 65 71 87 37 18
0.028 0.71 62 67 80 20 4
0.030 0.76 57 60 71
0.032 0.81 52 62
0.034 0.86 45 52
0.036 0.91 37 40
0.038 0.96 28 28
0.040 1.02 20
The above tables are from ASTM E 18.
Reprinted from the Annual Book of ASTM Standards, copyright American Society for Testing and Materials.
100 Barr Harbor Drive, West Conshohocken, PA 19428-2959