- High temperature ramp rates at 60°C (194°F) per minute: for increased thermal stresses to speed precipitation.
- Cooling unit comprises of LN2 system.
- Pressure gauges: allow operating pressures to be continuously monitored.
- Large dynamic range shaker: 1 to 60 GRMS with a bare table. High GRMS levels are used to enhance precipitation and low level with Modulated Excitation are used to increase detection.
- Lowest noise level: 72 dBA at 30 GRMS.
- One size chamber can accommodate wide range of product weights/sizes for high payload weights using replaceable springs.
- Safety Stop Mode Automatic Purge and Reset: Protects operators, products, and equipment
- Oxygen Monitor and Alarm: Interfaced to chamber LN2 system to ensure safe oxygen levels
- Door Interlocks with Programmable Features: Prevents door openings during operation, protecting operators
- High Volume Air Circulation System
- Air Distribution Through Adjustable Ducts or Slot: Optimizes configurable and adjustable airflow to the products
- Vibration table: perform 3 mode of vibration(single axis, double axis, triple axis)
- Displacement Levels: 3 times more displacement with dual strike impactors than conventional systems
- Color touch panel.
- HMI+PLC in one unit
- PCRC sheet body-Powder coated steel body assures corrosion resistant chamber and allows working of chamber at high temperature applications.
- Pre-attached data logger with data analysis software-Primary benefits of using data loggers is to automatically collect data 24-hour basis.Graph and table format of results can be produced automatically by the data logging software.
- Aesthetically designed-Designed according to the standards and principles underlining industry’s aesthetic values.
- Corrosion Resistant interior and exteriors-Corrosion resistant coatings like epoxy coatings are applied inside and outside the chamber to prevent against degradation due to moisture, salt spray, oxidation or exposure to a variety of environmental or industrial chemicals/ corrosive agents.
- Sturdy Construction- WEIBER chambers are built with robustness to withstand stress and strain, giving the chamber long life and ability to perform in extreme stress environments.
THE HALT PROFILE (Highly Accelerated Life Test):
HALT is a step stress process performed during the product’s prototype phase that determines a product’s operating limits, identifies design weaknesses, and identifies weak components. The prototype phase is the fastest and least expensive point to make improvements.
In the HALT process, the test sample is subjected to progressively higher stress levels. Thermal dwells, rapid temperature transitions, vibration, and a combination of temperature and vibration are employed to precipitate latent, inherent defects in the design, at the component level, or in the manufacturing process.
Beyond the precipitation of defects, HALT stresses the product sample to failure. Robustness of design and margin above the product’s intended operating level are determined. HALT is not a Pass/Fail test. It is process of discovery and design optimization.
HALT is a success when failures are produced, the root cause is understood, corrective action is implemented and product limits are understood and expanded. Information learned during the HALT process is used to develop a HASS screen for monitoring deviations in the manufacturing process.
The benefits of HASS include:
- Shorter design cycle = Quicker Time to Market.
- Usually less expensive, faster, and more effective than traditional pass/fail testing.
- Find and improve design margins.
- Produce a more rugged/reliable product with less field failures and warranty expenses.
- Reliable products lead to happy customers.
- Happy customers lead to increased profits/market share.
In HALT, every stimulus of potential value, temperature, all-axis vibration, humidity, UV, radiation, etc., can be used under accelerated test conditions during the development phase of a product to find the weak links in the design and fabrication processes.
The figure below shows the operating and destruct levels relative to the product specification.
A typical progression of HALT would be:
- Cold Thermal Step Stress
- Hot Thermal Step Stress
- Rapid Thermal Shock Stress
- Vibration Step Stress
- Combined Thermal and Vibration Stress
The chart below shows where design flaws were discovered during the HALT process and why all-axis vibration is important.
As you can see, the All Axis Vibration Step Stress (purple) discovers 45% of defects while the Combined Temperature and Vibration discovers (blue) discovers 20% of defects. Therefore, 65% of the flaws would have been missed without simultaneous, all axis vibration.
By stressing the product beyond its design specification, operational and destruct limits can be determined, and decisions can be made on how to increase these margins. Each weak link provides an opportunity to improve the design or the processes, which will lead to reduced design time, increased reliability, and decreased costs.
HASS is a post-production process that can be performed on 100% of product or a partial sample of units.The main goal of HASS is to precipitate and detect hidden or latent failures. It is used to verify that no new “weak link” has crept into the product.
Ultimately, its purpose is to prevent flawed units from reaching the end-user/customer. Typically, HASS stress levels are less than those used in HALT. However, they are generally more severe than anticipated in actual service. The goal is to use enough stress to find faults - but not enough to remove a significant amount of the product’s life.
The benefits of HASS include:
- Precipitates hidden or latent failures caused by poor workmanship or manufacturing processes.
- Verifies integrity of mechanical interconnects.
- Prevents flawed units from reaching the end-user/customer (infant mortality/ out of box failure).
- Detects changes in components and processes.
- Decreases warranty and field service costs.
- Increases customer satisfaction.
- Exposes process related variations in manufacturing.
- Uncovers problems caused by changes to both software and firmware.
- Uncovers component supplier quality issues and revision changes
The chart below shows where design flaws were discovered during the HASS process and why all-axis vibration is important.
HASS stress levels are less than those used in HALT, but are generally more severe than anticipated in actual service.
Testing will begin with the HASS profile determined to be the most effective during the Proof of Screen (POS) process. POS is a process showing that a screen does not damage good hardware and that the screen is effective in finding the defects present in a product.
This consists of running the desired HASS process 15 to 30 times to verify that the screen is not removing excessive life from the product.
Common defects revealed through HASS may include soldering problems, component failures, incorrect components, timing problems, IC Process change, IC Process problem, bent IC leads, electrical tolerance, mechanical tolerance and raw board problems.
Typical Stresses Used in HALT and HASS Testing
- Vibration applied over a broad frequency range (6 DOF(degree of freedom), 60 Grms, Random vibration energy to 10,000 Hz)
- Temperatures (-100°C to +200°C)
- High temperature rate of change (60°C / minute)
- Electrical loads
- More stresses (fluid pressure and viscosity, pH, unbalance, geometry, etc.)
- Combination of all loads
Weiber HALT-HASS chambers are double walled convection heated and cooled units. Outer body of our HALT-HASS chambers are constructed out of thick PCRC, pre coated corrosion resistant GI sheet duly pre-treated with primers and rust proofing and painted with long lasting stove enamel or elegantly powder coated. The inner chamber is made of heavy gauge stainless steel sheet of SS-304 grade). The gap between the walls is filled high grade mineral glass wool, which ensures maximum thermal efficiency in our chambers.
The unit is provided with single doors. This door is provided with magnetic door closer. This door is provided with lock and key arrangement. The unit is mounted on a sturdy steel frame. The unit is provided with various customized shelves in various permutations and combinations to suit individual requirements. The triple walled back of our HALT-HASS chambers are provided with two/Four/Six/Eight (size specific) air circulation fans for uniform maintenance of the temperature throughout the chamber.
HMI+ PLC IN ONE UNIT:
Weiber provides better automatic controls for the chamber by integrating HMI and PLC together. This special feature is compelling alternative to traditional methods and provides a simplified, reduced cost control system architecture.
It works by following operating steps:
- Sensors measure the physical quantity like temperature and convert them to electrical signal
- The actuation device acts upon that electrical signal
- At HMI interface between operator and chamber occurs.
- The machine operates with the logic design controls controlled by software.
- This signal is sent to the chamber by logic control devices and the chamber operates.
Basic features of HMI+PLC:
- Processor of 1.6 GHz: High clock speed processing PLC that enables speed up processing to the functions. With 1.6GHz processing speed, the PLC system is capable of multitasking, processing of large data volume, and high performance.
- Audio Output Alarm: Audio alarm alertin case of failures in any of the component controlling functions.
- 256 MB of RAM: PLC of 256Mega Byte memory for running programmes offers high memory space for installing of more programs
- COM Port: Com port provided for attaching RS 235/RS 485 cable.
- Increased Numbers of On - Board I/O peripherals (10-50): Maximum number of 50 I/O peripherals provided on request, to attach input and output devices to the HMI and PLC. Increased number of input and output peripherals allows adding of devices like printers, recorders, etc.,as per the need.
- Data Logging and Free Pprogramming Software: Attached data logger with input program software provided. Through data logging software, HMI and PLC collect datathrough sensors, analyse the data and save and output the results of the collection and analysis. Examples of the types of information a data logging system can collect include temperatures, sound frequencies, vibrations, times, light intensities, electrical currents, pressure and changes in states of matter.
CoDeSys (Controller Development System) software technology
Indirect heating system is provided in our units, comprising of air heaters made of high grade Kanthal A-1 wires of suitable wattage. The warm air is evenly distributed throughout the chamber through efficient motor fans ensuring very good temperature sensitivity.
HALT-HASS chambers are equipped with a Liquid Nitrogen (LN2 ) cooling system, which provides the rapid thermal change rates required to achieve maximum product stress.
The temperature inside our HALT-HASS chamber is controlled through Nano technology based HMI & PLC controller.
Temperature range of our standard Chamber is -100o C to +200o C. However we have the capacity to modify the same to suit the individual specialized requirements of our customers.
Temperature inside our HALT-HASS chambers are controlled with a sensitivity of + 1 o C or better.
The gap of 75 mm between the outer and the inner wall is filled with special grade glass wool to prevent thermal losses.
Triple walled back of unit is fitted with air circulation fans for maintaining temperature uniformly throughout the chamber
Features of Coaxial Circulation Fan:
- Vacuum impregnated stator winding with dr. back varnish under red baktol
- Best IR value
- Bright bar (EN - 8 class) shaft.
- Bush bearing of branded companies.
- Surge comparison testing in fans and pumps eliminates into turn short circulating of the stator.
- Pressure die-casted-rotor manufactured with zero error.
- Boats of high accuracy
Port hole: Port holes with silicon enclosure is provided at back side of the chamber. Through the port hole you can input sensors, wires and other test equipment. Silicone foam plugs have excellent temperature and humidity resistance and offer very good thermal insulation. Generally a single port hole is given but more numbers ca be increased according to customers request.
Vibration tests in three orthogonal directions can be achieved with the connection of a slip table with an electro-dynamic shaker. Our HALT-HASS Chambers are specifically designed to interface with all electrodynamic vibration generators in the Z axis or the X and Y axis (horizontal) with a slip table. This vibration table has one of the most consistent acceleration levels per unit area of any table presently on the market. Due to ease with which the table can be moved, the two main components of the WEIBER vibration test chamber System can be used independently from one another.
The horizontal slip table and a shaker, they share a same pedestal.
It has a good rigidity, and is easy to install and adjust, Vibration level is monitored and controlled via a tri-axial accelerometer block
- Large table top can accommodate multiple fixtures or large products
- Large number of mounting holes allows greater flexibility in mounting product
- Table is on an Airfloat pneumatic glide system for easy removal from the chamber for maintenance and fixture or product mounting
- “Easy-Lift” actuator switch makes raising and lowering the table for removal very easy
- Anodized aluminum table top eliminated aluminum oxidation
Customizable sizes and specifications are also available
Vibration Table Specifications
|Test Space Volume
|Internal Dimensions (WXDXH)mm
||860 x 860 x 860
|External Dimensions (WXDXH)mm
||-100° C to +200° C
|Temperature Change Rates
||10 to 60 ℃/min (as required)
|RS 232/485 interface
|Data file Backup System
|Full system security
|Automatic Temperature Setting
||760mm X 760mm (customizable as per chamber size)
||20 grms to greater than 60grms
||Single axis/ Double axis/Triple axis
||20Hz to 10kHz
|Degree of Freedom (DoF)
|Linear Vibration Aaccelerations
|Angular Vibration Accelerations
||Roll, pitch and yaw
- Board Level
- Chassis Level
- Component and Sub-Assembly Testing
- Computer Technology
- Full System Level Testing
- Power Supply
- Sub-Assembly Components
- Sub-Assembly Modules