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Temperature Management & Lab Animal Warming in Physiology and in Biology

 

 

Physiological - Biological Temperature Controller  TMP-5b

 

Optimized for seriously shielded environments in microelectrode laboratories, its output current is as smooth as the current of a lead battery (with the 12 V FINE DC end-stage, see below). This design fulfils all requirements of any sophisticated electrophysiology applications, even in close proximity to any, high impedance recording electrodes. Good references are the patch clamp setups with GigaOhm electrodes next to the heating elements.

 

General Description

 

We have developed a universal Physiological - Biological Temperature Controller construction that can be built with three different power end-stages, depending on the power requirement of the thermal process under control. Naturally, only one power end-stage can be installed in a Physiological - Biological Temperature Controller. The price of the Temperature Controller does not depend on the power end-stage installed in it. The appropriate power end-stage according to the requirements of the actual heating application should be chosen before placing an order.

 

        Click on the picture to get it in full size

 

The Physiological - Biological Temperature Controller is based on an internal microcontroller. The microcontroller communicates with the user through an intelligent menu system. Classic PID controllers modulate the RMS value of the output voltage. We implemented a learning algorithm into the firmware. It realizes the PID characteristics by adaptive slow PWM modulation through exponential output voltage changes. Furthermore we have built fault diagnostic features into the firmware. These unique fault diagnostic algorithms have been developed specifically for biological heating applications. For the details please see the User Manual.

 

Choice of the power end-stages

 

    - 12 V FINE DC: max. 36W. It is optimized for microelectrode laboratories, for seriously shielded environments.

        Its output current is as smooth as the current of a lead battery. This power end-stage fulfils all special requirements

        of any sophisticated electrophysiology applications, even in close proximity to any, high impedance recording electrodes,

        such as patch clamp setups.

 

    - 24 V pulsing DC: max. 75 W. It is a low voltage, electrically secure version for general purposes.

 

    - 115/230 VAC Huge-power version: up to several kW. It is optimal to control the temperature of great heated objects.

 

Specifications / Technical Data

 

The controlled temperature range: 0 Centigrade to 120 Centigrade, in 1 Centigrade steps

 

The available temperature range in a given application does not depend on the Physiological - Biological Temperature Controller, but on the heating device itself. In most cases the real temperature limit is less than 120 Centigrade. Higher temperatures can be reached with specially designed, larger power heating devices. If you require higher temperature than 50 Centigrade, please consult our engineers in advance.

 

Resolution of the measurement: 0.1 Centigrade

 

Hysteresis (approximately): 0.3 - 0.5 Centigrade. The actual hysteresis depends on the thermal capacity and the heat drain appearing on the heated object.

 

Both internal and external temperature sensors can be connected to the Physiological - Biological Temperature Controller. The internal/external sensor selector switch is located at the back of the Physiological - Biological Temperature Controller.

 

In our terminology, the expression "internal sensor" means that the temperature sensor is built into the heated object. In every heated object manufactured by Supertech Instruments there are built-in internal temperature sensors.

 

Display: 4 x 16 characters alphanumeric LCD with bright blue backlight

 

Programming: three pushbuttons on the front, in menu system

 

Automatic internal diagnostic and fault protection algorithms in the software

 

Flash program memory

 

Non-volatile EEPROM memory to store parameters used the previous time

 

Temperature sensor (either in internal or external arrangement): DS18S20 from Dallas Semiconductor

 

Dimensions of the instrument: 290 x 250 x 90 mm

 

Mains voltage: 100-120V or 220-230V (chosen by an internal selector switch, fixed in the factory)

 

Power consumption without output load, of the Physiological - Biological Temperature Controller: 80 VA

 

Weight: 2.8 kg

 

The complete User Manual of the Physiological - Biological Temperature Controller is available for download.

 

 

Small Animal Heating Pads

 

We offer a range of small animal heating pads. The appropriate size for the actual application can be chosen beforehand (depending on the size of your species).

 

Our animal heating pads can be used up to 50 Centigrade.

 

All heating pads are equipped with internal temperature sensors. It is recommended to use them instead of external temperature sensors. See the explanation below in the "Special Considerations" section.

 

Small animal heating pads can be cleaned with damp cloths, using non-aggressive solutions. They can be used in humid environments, but it is prohibited to immerse them in water, or use them under water!

 

On the side of every heating pad there is a M4 screw. This screw is the ground connection point. Electrically the metal enclosure of the heating pad is isolated from the internal circuitry. For the sake of perfect noise suppression you should connect the heating pad via the M4 screw to the central ground point of the electrophysiology rig.

 

Standard sized stainless steel heating pads

 

Our range of standard size heating pads:

    - 115 x 80 mm, 12W, (for mouse)

    - 170 x 115 mm, 24W, (for rat)

    - 330 x 145 mm, 36W, (for cat or rabbit)

 

            Click on the picture to get it in full size

 

The temperature variation between any two points of the heating pads is not more than 1 Centigrade (in worst case).

 

Standard size heating pads are covered in stainless steel. This provides great rigidity and mechanical protection. Standard heating pads are 12 mm in thickness, with 2 mm added for the legs.

 

Standard size heating pads employ a Physiological - Biological Temperature Controller fitted with 12V FINE DC or 24V DC power end-stage (depending on the size). Standard size heating pads work on 12V FINE DC.

 

Custom Size Heating Pads

 

Custom size heating pads can be ordered for special applications. The thickness of the custom size heating pads vary between 12 mm and 20 mm, depending on the actual size. Custom size heating pads are multilayer constructions. The top layer is a thin stainless steel plate, followed by a thick aluminum plate. The third (bottom) layer is a heat-insulating plastic plate. The thickness of the aluminum plate (middle layer) can not be decreased too much because it contains electronic circuits. There are active electronic current generators used as heating elements in the heating plates. The current generators are realized by electronic circuits (transistors, diodes and resistors). The heating pads are finished in stainless steel by default, and anodized black aluminum is available upon request.

 

 

Special Considerations about the External Temperature Sensors

 

An external temperature sensor (DS18S20 from Dallas Semiconductor) can be connected to the Physiological - Biological Temperature Controller. A tailored sensor in plastic enclosure, with 1.5 meter BNC cable is available in our selection. The actually used sensor can be selected with a toggle switch on the back of the temperature controller. However, we DO NOT RECOMMEND using an external temperature sensor. Eliminating an external temperature sensor is possible because there is a built-in internal temperature sensor in every heated object manufactured by Supertech Instruments. Please DO NOT use an external sensor, except under particular circumstances, for the following reasons:

 

1) Using an external temperature sensor, the average temperature of the heated object will be accurately the same as the setup temperature of the Physiological - Biological Temperature Controller, but a hysteresis (fluctuation in temperature) will appear. The reasons for the generation of the hysteresis are explained in the following paragraph. Using an internal temperature sensor built into the heating pad, the average temperature of the heated object will surely be less than the setup temperature of the Physiological - Biological Temperature Controller, but the hysteresis will be negligible. Occasional calibration of the internal temperature sensor will be necessary with a usual heated object. The calibration process is uncomfortable, but eliminating the hysteresis is essential because the target is a living animal or biological tissue. The change of temperature has a stimulating effect on biological objects that may disturb or modulate the experiment.

 

2) Heating tasks in biology present special difficulties. The heat capacity and the thermal time constant of the heated objects are huge because the object is usually an animal or living tissue. The thermal resistance of the external temperature sensor towards the heated object is significant (simply put, there is a bad thermal connection). This is true for both the technically realized heated objects (like our products), and heating pad - animal combinations. This results in significant hysteresis (6-8 Centigrade) when using an external sensor. It has been tested in different labs under different circumstances, but neither a hardware nor a software based solution has been found to eliminate this effect. As a good solution, we developed a predictive, learning algorithm for the Physiological - Biological Temperature Controller with a software running in the built-in microcontroller. This algorithm uses the device's internal temperature sensor. This way a stable, fine regulation of temperature can be achieved.

 

3) The heated object in most cases is an animal. The animal is not an "iron cube", it has its internal temperature regulation that may interfere with the predictive algorithm running in the microcontroller of the Physiological - Biological Temperature Controller, because the regulation process in the animal is not synchronized to the software-based control process.

 

4) DS18S20 is one of the most sophisticated temperature sensors available. It communicates with the host microcontroller in a fully digital way on a 1-wire bus, on standard TTL voltage level. Although it is a professional sensor, the TTL voltage level is much higher than the amplitude of the usual biological signals. As a result it generates digital noise, so it should not be placed in a highly sensitive shielded environment or in a tissue bath close to the working biological target.

 

5) Using an internal temperature sensor makes it easier to prepare the tissue or the animal, or set up the tissue bath. It is not necessary to keep the rectal or bath sensor always clean and sterile.

 

6) It is not necessary to buy an external temperature sensor.

 

It is possible to monitor the core temperature of the target animal exactly using a Biological Temperature Meter (see the description below).

 

The Choice of the External Temperature Sensors

 

    - DS18S20 temperature sensor: compatible with the Physiological - Biological Temperature Controller TMP-5x

        Main features:

        - Diameter: 4.5 mm, can be used as rectal sensor for larger animals (and maybe rats)

        - Digital, with excellent long term stability

        - Factory calibrated, with better than 0.1 Centigrade accuracy

        - Relatively strong and durable

        - Unshielded, should not be used close to high impedance recording electrodes

 

    - Pt100 temperature sensor with stainless steel coating: compatible with the Precision Biological Temperature Meter BTM-3a

        Main features:

        - Diameter: 3.0 mm, can be used as rectal sensor for rats (and maybe mice)

        - Analog, regular user calibration is needed for high accuracy

        - Relatively strong and durable

        - It can be shielded

 

    - Pt100 temperature sensor with epoxy coating: compatible with the Precision Biological Temperature Meter BTM-3a

        Main features:

        - Diameter: 2.6 mm, can be used as rectal sensor for rats (and maybe mice)

        - Analog, regular user calibration is needed for high accuracy

        - Vulnerable, careful handling required

        - It can not be shielded

 

    - Pt100 miniature temperature sensor : compatible with the Precision Biological Temperature Meter BTM-3a

        Main features (preliminary info, available soon):

        - Diameter: 0.9 mm, can be used as rectal sensor for mice

        - Length: 15 mm (excluding connector wire)

        - Analog, regular user calibration needed for high accuracy

        - Vulnerable, careful handling required

        - It can not be shielded

 

 

Precision Biological Temperature Meter V.3

 

BTM-3a Temperature Meter is a very popular piece of equipment for the following reasons:

    - It can be calibrated by the user to achieve an infinite level of accuracy. Its precision depends only on the master-gauge involved.

    - It has an analog voltage output for high resolution measurement and data logging on any 3rd-party DAQ device.

    - It employs industrial standard Pt100 sensors. This way any special thermal connection can be designed and

        constructed, supports others than the above listed default sensors.

 

Precision Biological Temperature Meter BTM-3a is a high accuracy temperature meter optimized for the temperature ranges of living tissues. The resolution of the measurement is 0.1 Centigrade and the accuracy of the Biological Temperature Meter can be trimmed as good as your temperature reference used for calibration.

 

        Click on the picture to get it in full size

 

The Biological Temperature Meter has a crucial, compulsory accessory, the Pt100 Transducer Box. It is a small piece of equipment in a plastic enclosure. The Pt100 Transducer Box is to be positioned very close to the Pt100 sensor. The cable length of the Pt100 sensor must be reduced as much as possible to keep the electric noise level at a minimum (not to interfere with the temperature measurement). The Biological Temperature Meter and the Pt100 Transducer Box are connected by a 1.6 meter long wire that is not sensitive to disturbing electromagnetic fields. The Pt100 Transducer Box is designed to accept any kind of Pt100 sensors. This feature provides the possibility of choosing the sensor that optimally fits the experimental environment. The only limitation is that the chosen sensor must be Pt100 type, but the size, shape and enclosure of the sensor can be freely chosen

 

Two versions of the Pt100 Transducer Box:

 

        Click on the picture to get it in full size

 

There are two internal potmeters built into the Pt100 Transducer Box, "Gain" and "Shift". Using these potmeters the error of the temperature measurement can be trimmed to absolute zero. It is always necessary to adjust these potmeters after changing the sensor, because commercial sensors have quite high tolerances, and this tolerance can be trimmed to zero. The accuracy of your measurement depends only on the precision of your temperature references used to calibrate the Pt100 Transducer Box. The price of the Pt100 Transducer Box is included in the price of the Biological Temperature Meter.

 

The Pt100 sensor is not included in the price of the Precision Biological Temperature Meter BTM-3a, neither in that of the Pt100 Transducer Box. To use these devices, a Pt100 sensor should be ordered from our selection, or any 3-rd party manufacturer.

 

Specifications / Technical Data

 

Measured temperature range: - 40 Centigrade to 120 Centigrade

 

Resolution of the measurement: 0.1 Centigrade

 

Display: 3.5 characters numeric LCD with backlight

 

Analog voltage output for PC-based DAQ systems: 0.1 V or 0.01 V per Centigrade (jumper selectable)

 

Temperature sensor: Pt100 (the equipment is compatible with any commercially available Pt100 sensor)

 

Dimensions of the Biological Temperature Meter: 200 x 160 x 75 mm

 

Dimensions of the Pt100 Transducer Box: 90 x 50 x 25 mm

 

Mains voltage: 100-120V or 220-230V (chosen by an internal selector switch, fixed in the factory)

 

Power consumption: 30 VA

 

Weight: 1.8 kg

 

The complete User Manual of the Precision Biological Temperature Meter is available for download.

 

 

Special Heaters and Unique Heated Equipments

 

On the one hand our Physiological - Biological Temperature Controller TMP-xx devices, thanks to their different power end-stages, are extremely versatile temperature controllers. They can manage every temperature regulation task in life sciences, only the task-specific "thermal interface" is needed. On the other hand our design engineers have several decades of experience in the field of temperature control, as we have developed many unique heating devices. These facts ensure that we can solve any special task in temperature management for biology and physiology. If you have any special request please do not hesitate to contact us. We will provide a great solution quickly, and at a reasonable price. The following two equipments are examples. Originally both were developed for specific tasks. Later, during design procedures of similar equipments, we decided to introduce them as standard products.

 

 

Heater for Microscope Stage

 

Heaters for microscope stages are custom-designed products, we can design any special heater pad for you. We design it together with you, according to your special considerations and requirements. The price is fixed in advance as a unit-price, because the different versions are similar to each other in both material and labor costs. This way we can focus on the professional aspects during the design process.

 

Usually the heaters for microscope stages are black, hard-anodized aluminum plates, with a thickness of 10 or 12 mm. They can also come with a matte (unglazed) finish. The aluminum provides great durability and rigidity. Openings on the heaters for microscope stages can be covered with a thick glass plate or without glass depending on the actual requirements.

 

In the discussion phase we can provide a schematic design proposal based on a drawing of the stage, plate, and other parts provided by the customer.

 

An example:

 

        Click on the picture to get it in full size

 

In the picture you can see a square-shaped heater. This model includes the thick glass cover. This style of heater is not suitable for inverted microscopes.

 

Microscope stage heaters can also be round. The outer diameter, the aperture, the nest of the chamber (if necessary), and the height of the focus plane are specified by the customer. The only limitation is that we have to take the space for the heater current sources into consideration. We use active electronic current generators as heating elements. The heater current generators are located around the oopening on the top or bottom side of the heater plate.

 

The temperature variation between any two points of the heater  is not more than 1 Centigrade (in worst case).

 

Heaters for microscope stages are equipped with internal temperature sensors. It is recommended to use them instead of external temperature sensors, please see the explanation above.

 

For using a heater for microscope stage you should buy a Physiological - Biological Temperature Controller assembled with 12V FINE DC or 24V DC power end-stage, depending on the actual design.

 

 

Tunnel Heater with Heating Pad

 

Tunnel Heaters are used to protect small animals against chilling from their back, as a result of the vertical heat radiation from their bodies in long term experiments. The internal surface of the Tunnel Heater is a heat radiator that keeps the upper side of the animal at the required temperature.

 

Tunnel Heaters are optional accessories for heating pads. Tunnel Heater are equal in length to the corresponding heating pads. The height of the tunnel heaters is proportional to the width of the heating pad.

 

For using a tunnel heater and a heating pad together, only one Physiological - Biological Temperature Controller is needed, assembled with a 24V DC power end-stage. The tunnel heater and the heating pad are connected, so they are heated up and controlled by the same temperature controller.

 

        Click on the picture to get it in full size

 

 

Prices

 

You can find the general warranty and shipping conditions in the beginning of the Price List page.

 

Physiological - Biological Temperature Controller (heater-only version) TMP-5b: 780 EUR

 

2-channel Physiological - Biological Temperature Controller (heater-only version) TMP-5c-twin with independent controllers and 12V FINE DC end-stages: 1300 EUR

 

*NOT available at the moment: Physiological - Biological Temperature Controller (cooler-heater version) TMP-6a: 1090 EUR

 

Standard size heating pads for small animals, with built-in digital DS1820 temperature sensor (compatible with the 12V Physiological - Biological Temperature Controller). Unit price: 80 EUR / dm2. The actual choice of the standard size heating pads:

 

Heating Pads with stainless steel top plate for small animals, with built-in digital DS1820 temperature sensor (compatible with the 12V Physiological - Biological Temperature Controller):

- 115 x 80 mm: 74 EUR

- 170 x 115 mm: 156 EUR

- 330 x 145 mm: 382 EUR

 

SMALL SIZED (smaller than 5 dm2) CUSTOM Size Heating Pad for small animals, with built-in digital DS1820 temperature sensor (compatible with the 12V or with the 24V Physiological - Biological Temperature Controller). Their thickness is 12 mm or more by default, depending on the actual size, excluding the small rubber feet. Smaller thicknesses are to be discussed before placing an order: 160 EUR / dm2

 

LARGE SIZED (larger than 5 dm2) CUSTOM Size Heating Pad for small animals, with built-in digital DS1820 temperature sensor (compatible with the 12V or with the 24V Physiological - Biological Temperature Controller). Their thickness is 12 mm or more by default, depending on the actual size, excluding the small rubber feet: 80 EUR / dm2

 

SPECIAL OFFER! Design work of unique, custom size heating pads for small animals according to your specification and requirements: FREE

 

Flat heating plate for stage of microscopes, with built-in digital DS1820 temperature sensor (compatible with the 12V Physiological - Biological Temperature Controller). Unit price, irrespective of the size: 370 EUR

 

SPECIAL OFFER! Design work of unique heatable plate for microscope stages according to your specification and requirements: FREE

 

Screw attachable heater assembly, in the power range of 1 to 36 W, with bipolar transistor based active heating circuitry, with built-in digital DS1820 temperature sensor (compatible with the 12V Physiological - Biological Temperature Controller): 130 EUR

 

Precision Biological Temperature Meter BTM-4a, compatible with any Pt100 temperature sensors (including the Pt100 Transducer Box): 350 EUR

 

Replacement Pt100 Transducer Box: 135 EUR

 

External digital DS18S20 temperature sensor with 1.5 m coaxial cable and BNC plug: 40 EUR

 

Pt100 temperature sensor with stainless steel coating and 0.5 m cable: 120 EUR

 

Pt100 temperature sensor with epoxy coating and 0.5 m cable: 35 EUR

 

Pt100 miniature temperature sensor with 0.5 m cable: 180 EUR

 

Tunnel Heaters with Heating Pads for small animals, with built-in digital DS1820 temperature sensor (compatible with the 24 V Physiological - Biological Temperature Controller):

- Tunnel Heater and 115 x 80 mm Heating Pad together: 148 EUR

- Tunnel Heater and 170 x 115 mm Heating Pad together: 312 EUR

- Tunnel Heater and 330 x 145 mm Heating Pad together: 764 EUR

 

 

 

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