GFL deep freezers are equipped with both microprocessor technique and an interface module for convenient remote control, monitoring and temperature recording via PC (compatible with labworldsoft® PC software). RS 422 and RS 485 are optionally available as another two transmission formats.
GFL deep freezers are manufactured using only high-quality, stringently tested materials that are particularly suitable for ultra-low temperatures. The units are extremely quiet, have been approved with the CE mark, are maintenance-free and have the German TÜV seal for "certified safety" (GS) based on the Federal German Equipment Safety Code.
The GFL deep freezer program includes chest and upright freezers with capacities ranging from 30 to 500 liters volume. There are 12 chest freezers with six different volumes, respectively, four Upright Freezers having tow different storage volumes. Both of these products are designed for temperatures of 0°C to -40°C, or -50°C to -85°C in an ambient temperature of up to 28°C: 12 deep freezers with 6 and 6 freezer cabinets and 3 differently sized usage areas (after removing the cover, the under counter deep freezers 6441 and 6481 offers the possibility to store freezing goods directly at the work place. Temperature ranges: 0°C to -40°C and -50°C to -85°C, volume of usage space: 96 litres, 3 drawers with castors).
Microprocessor-controlled temperature regulation
The microprocessor-controlled temperature regulator, with digital display of actual and set temperature values and digital setting for specified values, operates maintenance-free and is shock resistant. The regulator is battery-buffered by a constantly charged NC battery that maintains the display of the actual temperature and the alarm functions for 60 hours in case of a power failure. During operation on the line the battery level and the set temperature can be checked by touch control.
Energy saving deep freezers
The maintenance-free cooling unit, equipped with fully hermetically sealed high-performance compressors and an air-cooled condenser, ensures short cooling times. Non-flammable refrigerant. The all-around insulation comprises an up to 150 mm thick, seamless and diffusion-protected foamed-in polyurethane layer. This insulation is an essential precondition for energysaving operation. The quietly running compressors only give off around 400 W of heat to the environment at maximum cooling temperature.
Ex-proof inside cabinets
The inside cabinets are manufactured completely of stainless steel (material No. 1.4301), are corrosion resistant and easy to clean. They are free from ignition sources - an extremely important aspect when storing media with low flash points - and are ex-proof in accordance with BG-I 850-0, version 02/2009. The cooling air outlet is located at the front of the unit, meaning that explosive gases cannot be drawn in when the lid or door is opened. The magnetic sealing system reliably prevents freezing of the lid or door seals. All chest lids are balanced and easy to operate.
Chest freezers having a volume of 220 to 500 liters are also equipped with additional insulating cover plates on the cabinet. Upright freezers with storage volumes of 300 and 500 liters are equipped with three inside compartments (H 353 mm), each provided with an insulating door to prevent any loss of cold air. Optional shelves can also be installed in the compartments. On request, the cabinet can also be equipped with a set of drawers instead of the inside compartments.
Controlled access
The lids and doors of the freezer units can be locked, making unauthorised removal of material impossible. The easy-to-use control panel provides controlled access through the use of a key-operated security switch, ruling out any inadvertent temperature maladjustment.
Multiple alarm messages
As standard, the deep freezers come with a potential-free changeover contact for connection to an internal alarm system, or to the central I&C system. They are also provided with a connection for a piezoelectric buzzer for simple remote notification of alarms. In the event of a fault (e.g. excess temperature, under temperature, loss of power, sensor break/short-circuit, etc.), an optical and acoustic alarm is issued. The cause for the fault is shown in the display as a defined code number.
The limit values for alarms (1 – 20 K), for excess and under temperatures can be set individually by the user.
Other optional alarm messages can also be set by the user:

• Suppression of alarm message after a power failure (0 to 999 minutes); this feature is useful, for example, if emergency backup power systems are tested regularly.
• Suppression of alarm message on violation of a temperature limit (0 to 999 minutes). The set value remains stored until the next change is made. This can be useful, for example, when large quantities of refrigerated goods are removed/put into storage frequently.
• Suppression of alarm message on violation of temperature limits (0 to 999 minutes). The set value is cancelled when the set time expires. This can be useful, for example when refrigerated goods are removed/put into storage only occasionally

Powder-coated housing
The housings are made of powder-coated, electrolytically galvanised sheet steel. As a standard, GFL deep freezers come with double wheel swivel castors, two of which can be locked, for transport to the place of use and for mobile applications (castors for under counter deep freezers 6441 and 6481).
Intensive quality assurance
Intensive quality assurance with state-of-the art testing devices ensure trouble-free operation and long life.
Special makes
In addition to a wide range of accessories we also supply customised equipment on request, tailored to the individual requirements of tasks that demand special solutions for storage.

CO2/LN2 safety cooling system for 230 V a.c. (emergency power) or for battery operation (the supplied storage battery enables operation for approx. 60 hours). Safety cooling systems protect against non-regulated rises in temperature by keeping the temperature in the cabinet constant at a freely selectable value (0 to -70 °C) by controlled injection of LN2 or CO2 when the main cooling system fails. These systems can be installed in chest freezers with a volume of at least 70 liters and in upright freezers starting at a volume of 300 liters storage space. CO2/LN2 bottles not included.

Distribution lines are required of two or three CO2 bottles are connected simultaneously to the freezer unit. The CO2 bottles must be provided with a rising pipe and must not be connected to a pressure limiter. The distribution line for safety cooling system can be ordered complete with all requisite connectors, tubes and materials for wall mounting. CO2 bottles not included.

A heat exchanger is installed in place of the air-cooled liquefier. The advantage here is that the heat exchanger considerably reduces the heat given off by the unit to the environment, at the same time, expanding the permissible ambient temperature range in which the unit can be operated. Water supply is regulated by the freezer. The heat exchanger can be connected to a recirculation system or to the internal water supply system. (Connecting points on unit: screw fitting for presure hoses ½ inch* with coupling nut). A water cooling system can be installed in GFL deep freezers with a volume of at least 220 liters.
*not included

Ensures continuous recording of the inside cabinet temperature on pressure sensitive paper. The current measured value is recorded with constant, clear legibility without the use of expensive ribbons or ink. The chart recorder is designed for continuous operation and is equipped with three paper feed options. A paper roll (Item No. 13.608) is included in the scope of delivery. Recording time 15 to 368 days. It can be integrated in deep freezers with 70 and 100 litres, as well as in freezing cabinets starting at 300 litres of usage volume (Item No. 6950). When combining with other deep freezing devices, the dotted-line recorder is mounted in a separate housing (Item No. 6951).

Provides detailed documentation of the spatial and temporal temperature constancy in our Deep Freezers, when they must, for example, comply with the special approval guidelines defined by the US American Health Authority FDA. All requested test and measurement data are established at our factory using a calibrated test section and archived at GFL for one decade.

Upright freezers having a storage volume of 300 and 500 liters come with three compartments as standard equipment. As an option, each compartment can be sectioned with one additional shelf for optimal utilisation of the internal volume of the unit.

The cabinet of upright freezers can also be equipped with a set of four drawers in place of the three insulated compartments. These drawers are made of stainless steel with front panels made of 10 mm thick polystyrene insulating plates. Ball bearings and slide rails ensure easy and level motion.

Optimised utilization of the storage space is achieved using racks for boxes, microtiter and DeepWell plates.
The stainless steel drawers reduce overall weight and are easy to handle. Use of these drawers guarantees well-arranged and safe storage of the entire sample material. The boxes are made of water-resistant coated cardboard. There are three different dividers available for the boxes. The box capacity for storing samples can be varied, permitting the system to be adapted to a variety of applications.