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HFRR (High Frequency Reciprocating Rig)
/ Software
AutoHFR Software
On this page: Overview | Profiles | Specification
Overview
When evaluating the friction performance of lubricating oils the value of friction coefficient as a function of temperature may be of great interest. Boundary lubricant additives are frequently only active over a restricted temperature range and the ability to characterise this performance in one simple test is desirable.
By using the AUTOHFR software, you have complete flexibility when defining the test profile. Each profile is built up from a series of individual steps, and the temperature, frequency and stroke length can be varied during each step. The standard HFRR instrument can perform tests at temperatures up to about 150°C. For temperatures above this, an optional high power heater box can be used which allows tests at up to 400°C.
AUTOHFR records and displays various parameters during the test. The friction force between the specimens, the contact resistance (film) value and the lower specimen holder temperature are continuously displayed in a graphical format throughout the test, and are saved to the results file at the end of the test. Results files can be recalled and printed as required.
AutoHFR test data
The AUTOHFR test data is saved in a binary format. The test data can be converted into a text format by using the 'Export Data' option. This will allow the data to be opened using spreadsheet packages such as Excel, Star Office, Lotus etc. The new output data file is saved with a .txt extension. This file is a tab separated text file.
Running a test using profiles
The AUTOHFR uses lists of instructions called profiles to sequence tests. The profiles can be created and edited using the AUTOHFR 'Manage Profile' feature. The profiles are stored in a binary format and cannot be read or edited using standard text editing programs (such as Notepad or WordPad). The profiles can only be edited or created from the AUTOHFR program
Test Profile screenshot
Each profile is made up from a number of defined steps. A profile can have a maximum number of 20 steps.
The six step types
The step types are listed in the pull down menu next to 'Step Type' as shown below.
Profile Scratchpad
The test types available are defined below.
Test Type
Run at constant temp
Run and ramp temp
Hold at constant temp
Hold and ramp temp
Pause with message
User defined
Description
The instrument will run at fixed values of temperature, frequency and stroke length.
The instrument will run with fixed values of frequency and stroke
length.
You can set start and end
temperatures for the step. The
instrument will
attempt to control the temperature of the specimen
bath linearly between
these temperatures over the step duration.
The instrument will hold at the desired temperature. The pushrod will be stationary.
The instrument will attempt to linearly ramp the temperature from
the
specified start point to the
specified end point over the step
duration.
The pushrod will be stationary.
The test pauses displaying a written message.
All parameters can be varied.
The step parameters
The scratchpad is where the parameters for a step are edited. The parameters available are defined below.
Test Type
Step Duration
Output Interval
Test Load
Film Sensor Range
Start Temperature
End Temperature
Start Frequency
End Frequency
Start Stroke Length
End Stroke Length
Wait for start temp
to stabilise
Description
The duration of the step in hours, minutes and seconds.
The
step duration is limited to 9 hours,
59 minutes, 59 seconds.
The time interval in seconds that data from the instrument will be saved for export.
The test load that will
be applied during this step in grams.
NB: If two
consecutive steps have
different
loads then the software
will automatically ask you to change
the load, there is no need to
add a
"change load"
'Pause' message.
The value of the reference resistor used in the contact resistance
circuit (in Ohms). Possible values
are 10, 100, 1000, and 10000. Use
higher values
for higher viscosity lubricants. Typically 10 is used
for
fuel testing
and 100 or 1000 for lubricant testing. The film range is
selected by clicking
on the down
arrow to show the options available.
The temperature at the start of the step.
The temperature at the end of the step. The instrument attempts to
vary
the temperature linearly
between the Start and End Temperature
over the
duration of the step.
The reciprocating frequency at the start of the test, between 10 and 200 Hz.
The reciprocating frequency at the end of the test, between
10 and
200 Hz. The instrument varies
the frequency linearly between Start
and End Frequency over the duration.
The desired stroke length at the start of the test, between 200 and 2000 µm.
The desired stroke length at the end of the test, between 200 and
2000 µm.
The instrument varies
the stroke length linearly between Start and End
Stroke Length over the duration of the step.
This is only available for user defined steps. If it is set, the instrument
will stabilise the temperature
at the 'Start Temperature' before starting
the step. If this is not selected, the test will start immediately
and
the temperature will 'catch up' to the desired profile as the step is running.
NB
- 'Wait for start temp
to stabilise' is always on for all other step types, ie: all run and hold steps will wait for the start
temperature
to be reached before that step is started.
Recommended Specification
The software has been designed to run on Windows XP platform although the AutoHFR software can run on Vista but should to be set to administrator mode for full compatibility. Any current entry level PC will be sufficient. Please note that a serial port is required to communicate with the HFRR.
Processor (CPU)
Memory (RAM)
Hard Drive Storage
Display
Operating System
Connections
Optical
Intel Pentium 4 or AMD equivalent
1GB
20 GB (minimum disc space to install 160MB)
Display resolution set to 1024 x 768 pixels
Windows XP, Vista or Windows 7 (32 bit)
RS232 Serial Port (9 pin connector) eg: COM1
CDROM Drive
