Technical Notes
	AlfaTherm- High quality NTC Thermistors & Assemblies Customized Developments Special Assemblies Product Handling & Use
	AlfaTherm- High quality NTC Thermistors & Assemblies
	NTC Thermistors are temperature dependent semiconductor resistors with a negative temperature coefficient which exhibit a large electrical resistance change when subjected to relatively minute changes in body temperature. Thakarsons Thermistors have a negative temperature coefficient even higher than -5%/°C as compared to O.385/°C for Platinum Resistance bulbs.This property makes our NTC Thermistors an ideal temperature transducer. The NTC Thermistor is one of the most simple & versatile components available to electronic designers. Its unique characteristics permit easy solutions to many sensing, measurement & control problems which would otherwise require complex & critical circuitry. Thermistors are used in a wide range of applications including temperature measurements & control, temperature compensation in electronic circuits, inrush current surge suppression, power measurements & vacuum / partial pressure measurements.
	Resistance Temperature Characteristics
	The best empirical equation is said to be the Steinhart-Hart equation. 1/T=A+B (LnR) + C (LnR)3 Where T is the Temp in oK R is the Resistance @ Temp T A,B and C are the derived coefficients. However, over narrow temperature ranges the simplified R-T relationship based on b is expressed as follows: RT1 / RT2 = e ß{1/T1-1/T2} The Temperature Coefficient a = -ß/T2 (% / oC)
	Customized Developments
	The variables in the Thermistor Characteristics including R25, B, Dissipation constant, Time constant Tolerances, Curve Characteristics, Temp. range, Shape & Size, Packaging etc, create thousands of permutations and combinations. We therefore offer specially developed devices to suit individual customer requirements. For this it is necessary to provide full details of your requirements specs, features & applications.
	Special Assemblies
	Soft touch sensor assemblies, Surface Plate mounted devices, Deep well probes, Nuts & Stud assemblies/Probes, Level indicator Probes, etc. are also available to customer specifications & drawings. Applications include photocopying m/cs, automobiles, plastic moulding rn/cs, air-conditioning, boilers and heating equipment etc.
	Temperature Transducer Application Modules: T-TAM's
	Low cost, reliable & accurate temperature indication, alarms, cutouts & control units are also available to suit customer requirements, T-TAM features include 12Vdc, 24Vdc, 23OVac Units, and single/multipoint, visual, audio, flasher alarms and cutout/cutin functions.
	Product Handling & Use
	Thermistors are intrinsically safe devices, provided they are operated within the rated voltage current and temperature ranges. Normal mode of damage is to open circuit. In the case of glass body thermistors the leads should not be bent less than 3 to 5 mm from the glass body. Indirectly heated thermistors & glass envelopes should not be dropped.