Sensory laboratory: General information

Instruments for the professional execution of sensory tests

Criteria that THIEMT plans and equips sensory labs in accordance to:

• DIN EN ISO 8589 (“Sensory analysis – General guidance for the design of test rooms”)
• Standardization of test conditions (e.g. constant lighting conditions, temperature, humidity, test room design)
• Elimination of all disturbance variables (e.g. sounds, odors, light stimuli, influence of other persons, uncomfortable sitting position)
• Customer and sector specific requests – almost anything additionally to the indicated configuration options can be custom-made

Equipment

The type of equipment is independent of the sensory tests that are to be performed later because the different test types require all the same conditions.

The features of the test cabins are configurable individually. All other furnishings will be selected or custom-made as required.

The following information and equipment samples are based on experience. Individual requests and custom-made versions can also be taken into consideration, if technically realizable.

Premises in general

Ideally, a sensory lab features a square groundplan of at least 80–100 m² of space and 3 entrances from the corridor. Additionally to the preparation and test rooms a meeting room, storage room/cold store and an office for test planning and evaluation can be part of a sensory lab. There should not be any noise or odor pollution from adjacent rooms. Ultimately, the actual layout of the lab depends on the room size and the number of entrances.

Ventilation and air-conditioning technology

Recirculation air system

A recirculation air system with an air circulation of up to six times per hour should be installed for ventilation and odour removal in the test room.

Regulation of temperature and humidity

The standardization of the test conditions also includes the constant regulation of temperature and humidity, for example by an air condition system. To ensure that the test participants feel well, the following conditions should be met:

• Temperature: 20 °C ± 3 °C
• Relative humidity: 40–50 %

It is advisable to generate a slight overpressure in the test room and to suck off the air in the preparation room together with the odors of the sample preparation (ventilation and air-conditioning system provided by the customer).

Test room

The test room should be big enough for 8–12 test cabins and should have no direct access to the preparation room or test kitchen. The room height should be 2500–3000 mm. The total exclusion of daylight should be possible. The floor should be equipped with noise cancelling coverings. In general, attention should be paid to a neutral color scheme of the furnishings.

Preparation room

The backside of the test cabin acts as a kind of a wall unit of the preparation room including the work surfaces. The sample preparation, sample coding and presentation are carried out here. The materials of the ceilings, walls, floors and furnishings should be odorless and olfactorily inert.

The minimum equipment includes:

• Work surfaces for preparation, coding and presentation
• Sink
• Storage space (cupboards)
• Garbage containers
• Dishwasher if necessary

If the tested products are highly prishable or require preparation, the following additional furnishings are required:

• Fridge, freezer and/or air-conditioned cabinet
• Stove, oven, microwave for heating, cooking and baking
• Water bath, hotplates
• Exhaust hoods

Stationary test cabins

Mobile test cabins are recommendable, if there is limited space only or if multifunctional rooms should be used for testing purposes. Otherwise preference should be given to stationary cabins.

Materials:
The visible furniture surfaces are mostly consisting of melamine coated chipboard in light grey. The handles are made of stainless steel.

All cabins have the following standard furnishings:

• Partition wall with plinth panel and hatch leading to the preparation room
• Privacy screens between test cabins
• Lighting unit with different light sources
• Technology cabinet
• Ventilation
• Worktop for testing and preparation of the products and space for the probands to fill in the questionnaires
• Base cabinet with sliding doors on the preparation side
• Partition wall height adjusted to the ceiling height

Many configuration and expansion options are available. The option modules include, for example, various kinds of lighting control, the installation of spittoons and washbasins or the equipment with monitor holders and keyboard shelves. Special requests of any kind are possible.

Work surfaces

The basic configuration includes work surfaces made of solid core panels. For an extra charge mineral-based panels are available.
Options:

• Solid core panels
  • Light grey color, black dyed core
  • Properties of cladding panels: Water, dirt and moisture resistant
• Mineral-based panels (Corian ®)
  • Glacier white color
  • Various advantages compared to solid core panels:
    • Durability
    • Hygiene certificate
    • Suitable for large-size, seamless work surfaces
    • Impact resistance
    • Pore-free
  • The basin also can be made of Corian ®
  • Especially suited for tasting of beverages

Service hatch

The view into the preparation room/test kitchen during the sample handling should be reduced to a minimum. This is guaranteed by the hatch design. Furthermore, a traceable hygienic and easy cleaning is possible at any time.
Options:

• Hatch with sliding door (e.g. for beverage tests)
  • Equipped with a high quality guiding mechanism. The opening is balanced in any position – the so-called guillotine effect is prevented
  • Larger opening than the rotary hatch
  • Opened by screw handle from the preparation side
• Rotary hatch (e.g. for triangle tests)
  • Easy to clean and light-tight
  • Flushly embedded rotary table

Lighting unit

The lighting unit ensures a uniform and glare-free lighting of the workplace. It is delivered with three furniture luminaires by default:

• Cold light (daylight) with a color temperature of 5600–6200 Kelvin
• Warm light (artificial light) with a color temperature of approx. 3200 Kelvin
• Red light (green light alternatively)

On demand, black light also can be mounted.

Red and green light are used for color masking, black light (UV-light) is able to show the differences of chocolate fillings in layer thickness for example.

Technology cabinet

The technology cabinet, with doors on the proband side, serves maintenance and installation purposes. The lighting unit and cable guide are mounted in the cabinet, as well as the pc and monitor holder, if necessary.

Privacy screens

The lateral separators stick out 500 mm relative to the worktop and are permanently installed on height-adjustable metal legs. Additionally to the angular-shaped standard version, a version with a rounded shape is available for an extra charge.

Base cabinet

The base cabinet with a height-adjustable shelf is on the side of the preparation room. Kitchenware or other objects needed for the sample preparation can be stored in the cabinet. A plinth panel combined with a sealing lip connects the cupboard to the floor. By request, the plinth panel is equipped with a ventilation slit.

Communication circuit (proband/personnel)

The communication circuit enables a wordless communication between the test person and the test personnel. The beginning and end of a test cycle are signaled by a button press or by completion of the questionnaire.

Controlling the lighting situation

Some product tests require different lighting situations. If multiple products should be compared, potential color differences are often masked by switching to red or green light. In single product testings, however, a cold or warm lighting situation is usually chosen. The lighting can controlled for each cabin individually on the preparation side. Alternatively, the lights of all cabins can be set centrally with a bus system.

Hanging cabinet with two doors

If requested, the partition wall is equipped with a hanging cabinet on the preparation side. It can be used to store dishes or glasses, for example. Additional option modules are cabinet lighting and whiteboard surfaces.

Spittoon or sink

For tests that require spitting, washing, rinsing or flushing the product it is sensible to equip the cabins with spittoons or sinks. The simplest version is a spittoon made of stainless steel with a cold water faucet. Generally, all requests are realizable such as a ring-shaped water flush for example. An important note, however, is that the sink option requires the worktop to have a clear width of at least 1020 mm.

IT – computer, monitor, software und accessories

To store possible computer accessories in a space saving manner an extendable keyboard holder beneath the worktop and a monitor holder mounted to the technology cabinet are optionally available. On request the cabins can be equipped with computers and special software. The software is easy to use and allows questionnaires to be created individually and flexibly in all languages, has interfaces to common evaluation software and can be extended with an online reporting tool.

Options:

• Monitor holder rigid or height adjustable according to VESA standard
• Keyboard holder
• PC (without connection)
• Software

Pedestral

A pedestral can be used to create a level difference of 150–300 mm between the preparation and testing sides. Chairs of normal height can then be used. The pedestral has a PVC surface.

Mobile test cabins

according to DIN EN ISO 8589

The patent pending mobile test cabins are small enough to be passed through doors or elevators and can be deployed at any time without tools. Neighboring cabins are connected by ready made cable bridges (plug & play). One common supply cable can provide power for up to five cabins.

Equipment (excerpt):

• Big castors for transport; centrally lockable
• Sample hatch with vertical sliding door
• Light: three separately switchable light situations (white light, yellow light, red light)
• Control lamp: lights up, if the cabin is occupied
• Communication switch: light signal for the soundless communication between test persons and personnel
• Separate protective switch
• IT: wireless keyboard with touchpad and height adjustable 19" monitor; PC optionally available
• PC cabinet with lockable doors
• Blackout curtains; selectable color
• Cabin colour: light grey

Storage room/cold store

If larger sample amounts are handled or if the sensory lab is used intensively, a dedicated storage room or cold store may be useful.

Meeting room

An adjoining room with a large table, flip chart, projector, a video set and PC can be used for discussions, trainings and meetings of panels and panel chairmen before and after tests.

Office for planning/evaluation

A separate room with a desk, PC and software, that enables the statistical evaluation of the questionnaires, is recommendable for the planning and evaluation of the sensory tests.