9) This provides essential advice for assessment of the unit and must be read in conjunction with the performance criteria and the range statement of the unit and the Training Package Assessment Guidelines.

The Evidence Guide forms an integral part of this unit. It must be used in conjunction with all components parts of this unit and performed in accordance with the Assessment Guidelines of this Training Package.

Overview of Assessment

9.1)

Longitudinal competency development approaches to assessment, such as Profiling, require data to be reliably gathered in a form that can be consistently interpreted over time. This approach is best utilised in Apprenticeship programs and reduces assessment intervention. It is the industry-preferred model for apprenticeships. However, where summative (or final) assessment is used it is to include the application of the competency in the normal work environment or, at a minimum, the application of the competency in a realistically simulated work environment. It is recognised that, in some circumstances, assessment in part or full can occur outside the workplace. However, it must be in accord with industry and regulatory policy.

Methods chosen for a particular assessment will be influenced by various factors. These include the extent of the assessment, the most effective locations for the assessment activities to take place, access to physical resources, additional safety measures that may be required and the critical nature of the competencies being assessed.

The critical safety nature of working with electricity, electrical equipment, gas or any other hazardous substance/material carries risk in deeming a person competent. Sources of evidence need to be 'rich' in nature to minimise error in judgment.

Activities associated with normal everyday work influence decisions about how/how much the data gathered will contribute to its 'richness'. Some skills are more critical to safety and operational requirements while the same skills may be more or less frequently practised. These points are raised for the assessors to consider when choosing an assessment method and developing assessment instruments. Sample assessment instruments are included for Assessors in the Assessment Guidelines of this Training Package.

Critical aspects of evidence required to demonstrate competency in this unit

9.2)

Before the critical aspects of evidence are considered all prerequisites shall be met.

Evidence for competence in this unit shall be considered holistically. Each element and associated performance criteria must be demonstrated on at least two occasions in accordance with the 'Assessment Guidelines - UEE07 '. Evidence shall also comprise:

A representative body of work performance demonstrated within the timeframes typically expected of the discipline, work function and industrial environment. In particular this shall incorporate evidence that shows a candidate is able to:

Implement Occupational Health and Safety workplace procedures and practices, including the use of risk control measures as specified in the performance criteria and range statement

Apply sustainable energy principles and practices as specified in the performance criteria and range statement

Demonstrate an understanding of the essential knowledge and associated skills as described in this unit. It may be required by some jurisdictions that RTOs provide a percentile graded result for the purpose of regulatory or licensing requirements.

Demonstrate an appropriate level of skills enabling employment

Conduct work observing the relevant Anti Discrimination legislation, regulations, polices and workplace procedures

Demonstrated consistent performance across a representative range of contexts from the prescribed items below:

Design gas detection systems as described in 8) and including:

A

Accessing and interpreting gas detection needs and parameters.

B

Providing selection options based on parameters for gas detection and economic considerations.

C

Following checking and documentation procedures.

D

Applying relevant contingency management skills.

Context of and specific resources for assessment

9.3)

This unit should be assessed as it relates to normal work practice using procedures, information and resources typical of a workplace. This should include:

OHS policy and work procedures and instructions.

Suitable work environment, facilities, equipment and materials to undertake actual work as prescribed by this unit.

These should also be part of the formal learning/assessment environment.

Note:

Where simulation is considered a suitable strategy for assessment, conditions must be authentic and as far as possible reproduce and replicate the workplace and be consistent with the approved industry simulation policy.

The resources used for assessment should reflect current industry practices in relation to designing gas detection systems.

Method of assessment

9.4)

This unit shall be assessed by methods given in Volume 1, Part 3 'Assessment Guidelines'.

Note:

Competent performance with inherent safe working practices is expected in the Industry to which this unit applies. This requires assessment in a structured environment primarily intended for learning/assessment which incorporates all necessary equipment and facilities for learners to develop and demonstrate the essential knowledge and skills described in this unit.

Concurrent assessment and relationship with other units

9.5)

For optimisation of training and assessment effort competency development in this unit may be arranged concurrently with any of the following units.

UEENEEM056A Design explosion-protected electrical systems and installations gas atmospheres

UEENEEM057A Design explosion-protected electrical systems and installations gas atmospheres

UEENEEM058A Design explosion-protected electrical systems and installations dust atmospheres

7) This describes the essential skills and knowledge and their level, required for this unit.

Evidence shall show that knowledge has been acquired of safe working practices and designing gas detection systems.

All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies.

KS01-EM079A Gas detection systems

Evidence shall show an understanding of gas detection systems to an extent indicated by the following aspects:

T1 Maintenance procedures in hazardous areas that will ensure the integrity of the explosion-protection technique encompassing:

the purpose of a maintenance schedule;

the purpose and extent of ‘close’, ‘sample’ and ‘periodic’ inspections;

the features of each explosion-protection techniques that should be included in a maintenance schedule;

the impact of environmental conditions on explosion-protected equipment, including corrosion and frequency of maintenance;

the documentation requirements for recording the maintenance process and results;

the use of Standards in determining the requirements with which the design of explosion-protected apparatus shall comply.

T2 Techniques for the installation and maintenance of fixed gas detection equipment encompassing:

Use of manufacturer’s instruction manual; for example, operating instructions, adjustments procedures and operational limitations.

Installation and maintenance of Standards and/or Codes of Practice for gas detection equipment.

T3 Location of fixed sample points or sensors encompassing:

optimal sensing;

maintainability and ease of calibration; and

protection against environmental and mechanical damage.

T4 Gas and vapour releases encompassing—

the nature of a site; and

natural and mechanical ventilation.

T5 Common problems with fixed gas detectors.

T6 Calibration and response checking.

T7 Factors to consider in the evaluation and selection of portable and fixed gas detection equipment encompassing:

Requirements for gas detection for a given situation:

sources for obtaining data on physical chemistry of the gas to be detected; and

sources for obtaining data on the conditions under which the gas may be present.

processes of assessing the specifications of gas detection equipment against established requirements.

T8 Detecting gases and vapours encompassing:

apparatus capability and users’ knowledge;

propagation of gases - This includes release of gas and vapours, ventilation, density, temperature and location.

gases to be detected and not to be detected;

intended application;

environmental effects;

safety when monitoring for flammable gases where personnel could be present;

common properties of gases and vapours - This includes density of gases, vapours and their mixtures; effect of temperature on density; LEL and UEL of combustibles and toxicity.

the differences between detecting gases and vapours - These include added complication of evaporation, condensation and temperature effects of vapours and their effect on propagation, calibration and detection, including sampling.

T9 Oxygen deficiency and effects on safety encompassing:

chemical reaction of oxygen with solid products;

chemical reaction of oxygen with gaseous products; and

dilution of the air by displacement by some other gas or vapour.

T10 Measuring principles of catalytic sensors, electrochemical sensors, infrared sensors and semi-conductor sensors encompassing:

common applications;

limitations and safety;

interferences of other gases with the measurement; and

poisoning of the sensor.

NOTE: Detailed information on gas detection is given in AS/NZS 60079.29.2.

T11 Measuring principles of thermal conductivity sensors, flame ionization, detectors (FID), flame temperature analyzers (FTA), photo ionisation detectors (PID) and paramagnetic oxygen detectors.

T12 Selection of apparatus encompassing:

environment;

system response delay; and

gas to be detected with respect to measurement principles.

T13 Behaviour of gas and vapour releases encompassing:

rate of release;

density; and

temperature/pressure.

T14 Design and installation encompassing:

sensor, sampling or open path;

location;

site; and

environmental conditions.

NOTE: These include adverse weather, excess temperature, vibration and other mechanical interference, hosing, airborne contaminants and corrosion.

T15 Integrity and safety encompassing:

redundancy; and

protection against loss of power supply.

T16 Commissioning and scheduled maintenance encompassing:

sample lines;

diffusion sensor screens;

initial gas calibration;

adjustment of alarm set points; and

plans and records.

8) This relates to the unit as a whole providing the range of contexts and conditions to which the performance criteria apply. It allows for different work environments and situations that will affect performance.

This unit must be demonstrated in relation to the design of electrical systems for any classified explosive gas atmosphere hazardous area.

Generic terms used throughout this Vocational Standard shall be regarded as part of the Range Statement in which competency is demonstrated. The definition of these and other terms that apply are given in Volume 2, Part 2.1.