Portable Dynamic Hardness Testing Machines
( Model : DHT-6 )

• Sleek & handy design, comes in a slim briefcase, for carrying the machine.
• Mainly used to check hardness in confined spaces, on large & heavy components, permanently installed parts with
  low test expenditure.
• The machine has built in conversion facility for given material to convert ‘D’ value to Vickers (HV), Rockwell
  (HRB, HRC), Brinell (HB), UTS scales which can be selected by pressing arrow keys.
• The model operates on two numbers of pencil cells.
• 30 hardness scales for different probes selectable by feather touch keys.
• Alpha numeric display – 16 characters x 2 lines LCD with improved electronics, micro controller circuity & user
  friendly
• software. Display indicates selected material & scale combination & hardness value.
• Five numbers of probes D, G, SH, EX & C can be given in different combinations.
• Facility to connect dot matrix printer through centronics parallel port.
• Upto 100 readings can be stored in memory of the machine for printing purpose.
• Serial interface is possible with RS 232 port at an additional cost.
• Automatic calibration facility of probe is available through keyboard.
• Extra (Optional) Accessories such as – Standard test blocks, support rings, printer, serial interface, different types of
  probes are available.




Portable Dynamic Hardness Testing Machines


Technical Specification

Mesureing Ranges
1. For Standard Probe (D) / Short Probe (SH) / Extended Probe (EX) Scales (as follows) -
 HARDNESS / MATERIAL TEST RANGE AND ORDER CODE
BRINELL VICKERS ROCKWELL - C ROCKWELL - B SHORE D
 Steel and Cast
 Steel unalloyed /Low alloyed
80 - 647
ST / BHN
80 - 940
ST / VPN
20 - 68
ST / HRC
38.4 - 99.5
ST / HRB
32.5 - 99.5
ST / HSD
 High Carbon, High Chromium (12% & above) Cold Work tool steel - 80 - 898
HC / VPN
20.4 - 67.1
HC / HRC
- -
 S.G. Iron (CI with spheroided and nodular graphite) (GG-40-80) 131 - 387
SG / BHN
- - - -
 Grey Cast Iron
 Grade 15-40 (GG)
93 - 334
CI / BHN
- - - -
 Cast Al. Alloys non heat treated and quenched & tempered condition 30 - 159
AL / BHN
- - - -
 Copper Zinc Alloys (Brass) 40 - 173
BS / BHN
- - 13.5 - 95.3
BS / HRB
-
 Copper Al. and Copper Tin alloy (Bronze) 60 - 290
BZ / BHN
- - - -
 Wrought Copper Alloys (Low alloyed) 45 - 315
Cu / BHN
- - - -
 Stainless Steel& High temp. resistant Steel. 85 - 655
SS / BHN
85 - 800
SS / VPN
19.6 - 62.4
SS / HRC
46.5 - 101.7
SS / HRB
-

2. For Heavy Probe (G) scales (as follows) -
 HARDNESS / MATERIAL TEST RANGE AND ORDER CODE
BRINELL ROCKWELL - B
 Steel & Cast Steel / Unalloyed and Low alloyed
90 - 640
ST / BHN-G
47 - 99
ST / HRB-G
 Grey Cast Iron Grade 15 - 40 (GG) 90 - 315
CI / BHN-G
-
 S.G. Iron (CI with spheroided and nodular graphite) (G.G - 40, 80) 125 - 350
SG / BHN-G
-

3. For Low Energy Probe (C) scales (as follows) -
 HARDNESS / MATERIAL TEST RANGE AND ORDER CODE
BRINELL VICKERS ROCKWELL - C SHORE D
 Steel & Cast Steel / Unalloyed and Low alloyed 80 - 683
ST / BHN-C
80 - 996
ST / VPN-C
20 - 69.5
ST / HRC-C
31.9 - 99.6
ST / HSD-C

Dimensions (Approx.) -
 Probes
 Standard (D)  Dia. 25 x 150 mm long.
 Short (SH)  Dia. 25 x 100 mm long.
 Extended (EX)  Dia. 25 x 150 mm long.
 Heavy (G)  Dia. 30 x 255 mm long.
 Low energy (C)  Dia. 25 x 145 mm long.
 Digital Display Unit  -  188 (L) x 105 (W) x 64 (H) mm.
 
 Measuring Accuracy -
 Average Measuring deviation ±1% referred to D = 800 on Standard “D” Test Block at a particular test location
 Weight (Approx.) -
 Probe (Standard) - 150 gms.
 Display Unit - 325 gms.
 ‘D’ scale standard test block - 3000 gms.
 Total Weight - 7 kg. of Machine (with all accessories & carry case)
 Operating Temp. Range -
 0°C to 50°C

Field of Application
 FIELD  FOR D/SH/EX PROBE  FOR G PROBE  FOR C PROBE
 Prepration of the surface to be tested  N 7 ( 66 )  N9  N5
 Max. roughness depth RL  10 microns  30 microns  2.5 microns
 Av. roughness depth Ra = Cla = AA  2 microns  7 microns  0.4 microns
 Min. weight of the test piece……….
 - of compact shape
 - on solid support
 - coupled
 5 kg.
 2.5 kg
 0.1 to 2 kg.
 15 kg.
 5-15 kg
 0.5-5 kg.
 1.5 kg.
 0.5-1.5 kg
 0.02-0.5 kg
 Min. thickness of test piece coupled  5 mm
 15 mm  2 mm
 Min. thickness of layer with surface hardening  0.8 mm  -  0.2 mm
 Indentation of the test tip with 300 HB specimen……………
 Hardness -
 Diameter
 Depth

 0.6 mm
 13 micron
 -  -
 Min. bore dia. of the specimen (only for short probe)  100 mm  -  -

With standard support ring machine can work on a minimum radius of 60 mm convex or concave. For lesser job dia. suitable additional support rings can be provided. (Ref. Extra accessories).

Power Supply Conditions
Dry cell batteries (1.5 VDC x 2 Nos.) ; Size - AA, Type - R6.

Standard Accessories
• Probe (Normally ‘D’, if specified other ProbeCan be supplied in place of ‘D’) - 1 No.
• Digital display unit - 1 No.
• Standard test block calibrated in ‘D’ Scale - 1 No.
• Brush for cleaning probe - 1 No.
• Carry case for Machine - 1 No.
• Instruction manual - 1 No.
• Coupling Jelly - 50 gms.

Extra (Optional) Accessories
Standard Test Block of any hardness.
Support rings for smaller radius for -

• (SR 1) Convex, Concave, Cylindrical, Spherical radius 30 to 60 mm
• (SR 2) Convex cylindrical radius 14.5 to 30 mm
• (SR 3) Convex cylindrical radius 10 to 15 mm
• (SR 4) Concave cylindrical radius 16.5 to 30 mm
• (SR 5) Concave cylindrical radius 12.5 to 17 mm
• (SR 6) Concave cylindrical radius 11 to 13 mm.

Serial Interface (Windows 98 Based).

80 Col. Dot Matrix Printer.
Different types of Probes -

• Standard (D)
• Short (SH)
• Extended (EX)
• Heavy (G)
• Low Energy (C)