Retrofit of Universal Testing Machine
Retrofit, maintenance and repair of universal testing machines of any brand, electromechanical or servo-hydraulic, starting with a diagnostic of the machine.
The Biopdi retrofits, maintains and repairs universal testing machines of any brand, electromechanical or servo-hydraulic. The service starts with a diagnostic of the frame, the drive and the measurement system, and returns the machine testing to current standards, with a modern controller and software when retrofitted, ready for a new calibration to ISO 7500-1 (ABNT NBR ISO 7500-1 in Brazil). The retrofit can include the BioLab software, developed by Biopdi.
This page is written by a manufacturer: Biopdi designs and builds the M2 line of universal testing machines, with the BioLab software. That is why our assessment also tells you when your machine is not worth upgrading. Below you will find what changes for each type of machine, the criteria for deciding, the signs of failure and what happens after the service.
What is a universal testing machine retrofit
A retrofit is a modernization: the frame stays, the control and measurement technology changes. Maintenance, repair and calibration are separate services, and the four complement each other.
| Service | What is done | When |
|---|---|---|
| Preventive maintenance | Inspection, cleaning, lubrication, retightening and replacement of wear parts at defined intervals | While the machine is working, to keep it that way |
| Repair (corrective maintenance) | Find the cause of the failure and replace or repair the failed part | When the machine stops, measures incorrectly or triggers an alarm |
| Retrofit (modernization) | Keep the frame and replace the technology generation: control, measurement, software and, if needed, the drive | When the electronics are obsolete, parts are unavailable or the software no longer meets the standards |
| Calibration | Compare the indicated force with that of a traceable reference standard and assign each range to a class | At most every 12 months and always after a major repair or adjustment (ISO 7500-1, NBR ISO 7500-1 in Brazil) |
What is usually replaced, by machine type
The scope of each retrofit is defined by the diagnostic. The lists below show what is assessed for each technology and what, depending on its condition, gets replaced.
Electromechanical machine
The force comes from a motor that turns ball screws and moves the crosshead. The diagnosis evaluates the machine and, depending on the result, the retrofit may replace:
- controller and force and position measurement electronics
- testing software, test methods and reports
- crosshead position sensor
- motor and servo drive, when they are at the end of their service life or parts are unavailable
- control panel, buttons, limit switches and emergency stop
- load cell, only if it is damaged or outside the range of the tests
Usually kept: frame, columns, crossheads, screws and guides in good condition, grips and fixtures.
Servo-hydraulic or hydraulic machine
The force comes from an oil-filled cylinder controlled by a valve. In addition to the electronics, the hydraulic circuit is part of the diagnosis:
- controller and measurement electronics
- testing software, test methods and reports
- force transducer (load cell or pressure transducer) and piston displacement sensor
- servo valve or proportional valve
- hydraulic power unit: pump, filters, oil and hoses
- cylinder and rod seals, when there is leakage
Usually kept: frame, columns, heads, undamaged cylinder, grips and compression platens.
The benchmark: what a new Biopdi machine has
To compare your machine with a current one, these are the features of the M2 line. They are the benchmark for a new machine, not the scope of the retrofit, which comes from the diagnostic.
- 1
Force measurement interchangeable load cells, class 1 per ISO 7500-1 (ABNT NBR ISO 7500-1:2023)
- 2
Crosshead position optical sensor with 0.0001 mm resolution
- 3
Strain up to 4 extensometer or LVDT channels, with automatic recognition
- 4
Stored calibration calibration data in non-volatile memory, independent of the computer
- 5
BioLab Software 11 test configurations, saved standards and methods, reports in PDF, HTML and CSV
- 6
Control panel and emergency stop control buttons, emergency stop and optional limit switch
Retrofit or new machine: how to decide
New electronics will not fix a poor frame. The decision starts with the mechanical condition.
| Criterion | Retrofit makes sense | Mechanical overhaul or new machine |
|---|---|---|
| Frame and stiffness | Straight columns, crossheads and heads without deformation, secure fastenings | Column bent by off-center loading, head or grip seat deformed |
| Guides and screws (electromechanical) | No noticeable backlash between screw and nut; guides and bushings with normal wear | Large backlash in the screw and nut assembly or worn guides, which require mechanical overhaul first |
| Cylinder and rod (hydraulic) | Leakage solved by replacing seals; rod and cylinder barrel without deep scratches | Scored or deformed cylinder or rod, which requires new parts for the most expensive component |
| Capacity and stroke | The maximum force and the stroke meet today's tests and those of the coming years | The test specimens have exceeded the capacity or do not fit in the test space and stroke |
| Mechanical parts | Wear parts available or manufacturable | Structural part with no replacement available and no way to manufacture it at a reasonable cost |
| Standard the laboratory works to | The standard requires class 1 and the frame, in good condition, can achieve it | The new test requires something the frame cannot do, such as cyclic testing on a static machine |
Why the frame comes first
If the frame cannot be calibrated, has backlash or broken parts, replacing the electronics will not improve performance (Quality Magazine, 2003). ISO 7500-1 itself only allows calibration of a machine in good condition, after a general inspection of the guides, grips, fixtures and axial force application.
A simple backlash check
Test a very stiff specimen and look at the force × position curve. A plateau where the position moves and the force stays flat near the weight of the crosshead indicates excessive backlash in the lead screw thread (Quality Magazine, 2003). With a new controller, this backlash turns into force and strain control error.
The class the standard requires
Most test standards require a class 1 machine: an indication error of up to ±1.0% of the measured force and repeatability of up to 1.0%, valid above 200 times the indicator resolution (ISO 7500-1). If the frame cannot reach that, a retrofit will not solve it.
When the answer is a new machine, the comparison of capacities, strokes and test space widths is on the page for the Biopdi universal testing machine, and the universal testing machine guide explains how to choose the capacity based on the test specimen.
Universal testing machine maintenance and repair
Preventive maintenance prevents downtime; repair fixes downtime that has already happened.
Preventive maintenance
Done at set intervals, while the machine is running. Typical items are lubrication of ball screws and guides, cables and connectors, emergency stop and limit switches, grips and, on hydraulic machines, oil, filters, hoses and seals.
Two manufacturer references for hydraulic machines: preventive oil and filter change every 2 years (ZwickRoell) and a maximum service life of 6 years for the hose assembly, counted from manufacture and including storage time (DIN 20066, cited by Instron). Follow your machine's manual when it is stricter.
Repair (corrective maintenance)
It starts with finding the cause: measurement, control, drive or mechanical parts. Good metrological practice is to calibrate or verify before the repair, to record the as-found condition of the machine, and again after the repair, as required by ISO 7500-1 (ABNT NBR ISO 7500-1 in Brazil).
A damaged load cell can sometimes be repaired if it has not been mechanically deformed, always followed by a new calibration. If the repair needs a part that is no longer available, it is time to consider a retrofit.
Signs that the machine needs technical service
The table helps you describe the problem and avoid making it worse until the service visit.
| What you see | Possible cause | What to do before calling |
|---|---|---|
| Force zero that does not return or drifts | Faulty load cell or cable, oxidized connector, electronics; on hydraulic machines, oil still cold | Record the reading with no specimen, check the cable and connector; on hydraulic machines, warm up before zeroing |
| Force drops with the command held (hydraulic) | If the pressure gauge also drops: internal leakage, seal or valve. If only the reading drops: measurement | Compare the pressure gauge with the indicated value, look for oil on the rod and do not open the pressurized circuit |
| Noise, vibration or jerky crosshead motion | Lack of lubrication, backlash in the screw and nut, worn guide, belt or drive | Stop the test, record the speed at which it happens and do not force the machine |
| Leakage or oil overheating | Hose, fitting, seal, clogged filter or insufficient cooling | Switch off the hydraulic power unit, note where the oil is and the temperature |
| Software does not open, does not communicate or does not run on the new computer | Unsupported operating system, old interface, license or data acquisition board | Export test methods and results before any computer replacement |
| Failed calibration or a worse class | Load cell, electronics, frame alignment or mechanical wear | Keep the "as found" certificate: it helps find the cause |
Before requesting service, gather the brand, model and capacity from the nameplate, photos of the frame and the control panel, the error message, the latest calibration certificate and a copy of the test methods and results from the software. Take the opportunity to review the machine's safety with the article on NR-12 (Brazilian machinery safety regulation) in testing machines.
After the retrofit: calibration to ISO 7500-1
A refurbished machine should only issue test reports again after it has been verified. Calibration is what proves the work was successful.
When to calibrate
Under ABNT NBR ISO 7500-1:2023 (the Brazilian adoption of ISO 7500-1), after a repair or major adjustment, after relocation involving disassembly and, in normal use, within 12 months. A retrofit or a repair of the measuring system falls under the first case.
What to check on the certificate
The class of each force range (each load cell has its own), the lower limit from which the class applies and any anomalies found in the general inspection. The verified range must cover the forces the laboratory actually measures.
Extensometer and accreditation
The extensometer used with the machine is calibrated to ISO 9513 (ABNT NBR ISO 9513 in Brazil). If your quality system or your customer requires an accredited certificate (Cgcre/RBC in Brazil), have the calibration done by an accredited laboratory.
The calibration procedure step by step, classes 0.5 to 3 and examples of how to read the certificate are in the article on universal testing machine calibration to ISO 7500-1.
Brands we service and how service works
Any brand, electromechanical or servo-hydraulic, from diagnosis to training.
Biopdi services universal testing machines from any manufacturer, including older machines from Brazilian and foreign manufacturers that still run with an analog indicator, a paper chart recorder or software that does not run on current computers. Our service is technical and independent: Biopdi is not a representative or authorized service center of other manufacturers.
Older models that often come in for retrofit
A retrofit usually makes sense for machines whose frame is still in good condition but whose electronics, indicator or software can no longer be replaced. Some examples of older models still in use in Brazilian laboratories:
- EMIC, DL series: DL 2000, DL 10000 and DL 30000, electromechanical.
- Instron: 4400 series (such as the 4411), 5500 series (such as the 5569) and 3300 series (such as the 3369), as well as older servo-hydraulic machines.
Manufacturer and model names are used only to identify the machine; the trademarks belong to their owners. Biopdi is not a representative or authorized service center of these manufacturers. Other brands, Brazilian and imported, are also serviced.
1. Diagnosis
Based on the information and photos you send, the team evaluates the frame, the drive, the force and position measurement, the software and, on hydraulic machines, the circuit. The diagnosis is where the decision between repair, retrofit or a new machine is made.
2. Proposal
The scope comes in writing: what will be replaced, what will be kept and why. If the frame is not worth it, the proposal says so and recommends the alternative.
3. Execution
Replacement and adjustment of the components in the scope, setup of the tests the laboratory uses and functional testing before the machine is released.
4. Training
Operators learn the new routine: setting up the test, saving test methods, generating reports and performing the daily checks.
Frequently asked questions
The most common questions before refurbishing or repairing a testing machine.
What is a universal testing machine retrofit?
It is the modernization of an existing machine: the frame (base, columns and crossheads) is kept and the control, measurement, software and, when needed, the drive are replaced. The goal is for the machine to test to current standards again without the cost of a new frame.
Does Biopdi retrofit machines from other brands?
Yes. Biopdi performs retrofit, maintenance and repair of universal testing machines of any brand, Brazilian-made or imported, electromechanical or servo-hydraulic. Biopdi is not a representative or authorized service center of other manufacturers; the service is based on the diagnosis of the machine.
Does Biopdi retrofit EMIC DL or Instron machines?
Yes. Machines such as the EMIC DL series (DL 2000, DL 10000, DL 30000) and the Instron 4400 series (such as the 4411), 5500 series (such as the 5569) and 3300 series (such as the 3369) go through the same process: diagnosis of the frame, drive and measurement, and a proposal for retrofit, maintenance or repair. The names are mentioned only to identify the machine; the brands belong to their respective manufacturers.
Is it worth buying a used universal testing machine and retrofitting it?
It can be, if the frame is sound and the capacity and stroke meet your tests. Before buying, ask for the brand, model, capacity, photos of the frame and control panel and the latest calibration certificate, and check the columns, guides, screw or cylinder. The diagnosis after purchase defines the retrofit and, at the end, the machine must be calibrated to ISO 7500-1 (ABNT NBR ISO 7500-1 in Brazil).
Is it better to retrofit or buy a new machine?
A retrofit makes sense when the frame is sound, with no bent columns, no excessive backlash in the lead screw and no damage to the cylinder, and when the capacity and stroke still cover your tests. If the frame is compromised or your lab has outgrown the capacity, a new machine is usually the better choice. The diagnostic answers this for your machine.
What is replaced in a retrofit?
It depends on the diagnostic. Usually the controller and measurement electronics, the software and the sensors. Sometimes the motor and servo drive on electromechanical machines, or the valve and hydraulic power unit on servo-hydraulic machines. The load cell is kept if it is in good condition and can be calibrated.
What is the difference between retrofit, maintenance and repair?
Preventive maintenance keeps the machine running at set intervals. Repair, or corrective maintenance, fixes a failure. A retrofit upgrades the machine's technology generation while keeping the frame. All three end the same way: force verification before the machine issues test reports again.
Can a servo-hydraulic machine also be retrofitted?
Yes. Besides the controller, measurement system and software, the diagnostic covers the servo valve or proportional valve, the hydraulic power unit (pump, filters, oil and hoses) and the cylinder seals. The scope comes from the assessment of each item.
Does the machine need calibration after a retrofit or repair?
Yes. ISO 7500-1 (ABNT NBR ISO 7500-1:2023 in Brazil) requires a new verification after a major repair or adjustment and after relocation involving disassembly, in addition to the interval of up to 12 months. Until then, the machine should not issue results that depend on its class.
Are calibration and RBC accreditation the same thing?
No. Calibration compares the indicated force with that of a traceable standard. Accreditation by Inmetro (Cgcre/RBC, Brazil's national accreditation body and Brazilian Calibration Network) recognizes the competence of the laboratory performing the calibration, and is required by contract, by the customer or by the quality system. If your lab needs an accredited certificate, have the calibration done by an accredited laboratory.
What signs show that the machine needs maintenance?
A force zero that drifts, force that drops with no command applied, noise or chatter in the crosshead, oil leaks or very hot oil, software that does not communicate, and a failed calibration. In these cases, stop the machine, write down what you observed and contact technical support.
What information do I need to request a quote?
The make, model and year of the machine, its capacity, its type (electromechanical or servo-hydraulic), the tests and standards your lab runs, what is not working, and photos of the nameplate, the frame and the control panel. The price and machine downtime depend on the scope defined in the diagnostic.
Request a diagnosis of your machine
Describe the machine: brand, model, capacity, type (electromechanical or servo-hydraulic) and what is not working. Our team will reply with the next step and, after the diagnosis, with a proposal.
Reply within 24 business hours
A proposal covering capacity, fixtures and the standards met, not just the price.
Configured for your test
Scope defined from the diagnosis: what to replace, what to keep and whether the frame is worth retrofitting.
Testing machine manufacturers
Diagnosis, execution, training and technical support by the team that designs and manufactures the Biopdi line of universal testing machines.