Thin Film Platinum Precision Temperature Sensor TYPE SA/SB/SC/SD SERIES

Transcription

1 Thin Film Platinum Precision Temperature Sensor TYPE SA/SB/SC/SD SERIES MEGGITT SENSORS HUMIDITY, POSITION TEMPERATURE LIQUID LEVEL SURFACE MOUNT DEVICES WIRE LEADS, PC PINS This High Precision Thin Film Platinum Resistance Temperature Detector (Pt-RTD) consists of a thin film deposited Pt plus a less expensive metal wire (e.g.. Pd). This sensing element has a dramatic cost advantage against conventional Pt Sensors yet giving the same performance. The Pt-RTD Sensors can withstand temperatures ranging from -25 C to 8 C while normal operating temperature is between -5 C to 65 C, depending upon the customer's application. Meggitt, a thin film specialist, has extensively provided Pt-RTD with various resistance values (1, 5 and 1 C) and TCR's (375, ppm/ C). MEGGITT SENSORS KEY FEATURES NEAR LINEAR RELATIONSHIP (TEMP. & RESISTANCE EXTREMELY STABLE UP TO 8 C VERY PRECISE ACCURACY (±.5% & ±.15 C) MEETS IEC751 CLASS "A" EXCELLENT RELIABILITY PLATINUM ELEMENT SUITED TO TEMPERATURES -5 C TO +6 C MASS AIRFLOW SENSING POSSIBLE MEGGITT ELECTRONIC COMPONENTS SALES ACTION DESK TEL: ( ) FAX: ( ) sales@megelec.co.uk WEB SITE: LOG No FO739 ISSUE 4 5 Pages 6-1

2 TYPE SA/SC SERIES ELECTRICAL TYPE SA/SB/SC/SD SERIES (Page 2 of 5) Type -5 C ~ 5 C SA11 SA51 (Glass Coated) SA12 1 SA11 (Ceramic Tube) -5 C ~ 6 C SC11 SC51 SC12 SC11 Nominal Value at C 1R 5R 1K 1R T.C.R. ppm/ C Tolerance at C Class A ±.6% Class B ±.12% Class C ±.24% Class A ±.6% Class B ±.12% Class C ±.24% Response Time 9% AIR 1m/sec. 1 seconds Self Heating AIR 1m/sec. 2.5mW/ C 2.mW/ C 2.mW/ C 5.mW/ C N.B. Tolerance class A (±.6% at C) cannot be offered in all packages - please enquire A± GLASS COATED B±.15 C± Standard Special CERAMIC TUBE A±1. 6. B±.2 3. C±.2 8. All Dimensions are nominal and in mm unless othrwise shown.do Not Scale. TYPE SB SERIES ELECTRICAL Nominal Resistance at C: Temperature Coefficient of Resistance: Resistance Tolerance at C - Class B: Class C: Class D: Maximum Applied Current: Insulation Resistance: Thermal Response Time (9%, Air, 1m/second) - Self-heating (Air, 1m/second) - Operating Temperature Range - 1 ohms ±1.2 ohms, 375 ±.12% ±.24% ±.48% 1mA >1 Meg ohms 2 seconds maximum 5 seconds maximum 6 seconds maximum 5mW/ C 6mW/ C 7mW/ C -5 C to +15 C -2 C to +15 C -2 C to +15 C

3 TYPE SD SERIES TYPE SA/SB/SC/SD SERIES (Page 3 of 5) The SD series is a packaged probe specially designed for range/oven temperature control application. Meggitt Electronic Components can provide various probes upon customers' request with superior manufacturing and design capabilities. To assure quality and reliability of probes, 1% of the products undergo reliability test prior to delivery. Product quality is recognised by CSA (Certificate No: LR ), UL (File No: E ) and AGA (Report No: 135-Z2123). In addition the SD series probes are approved by worldwide leading manufacturers of ovens. Please contact us for more detailed information. The SD series is normally custom designed and can be offered with a variety of leads and packages to suit ever user requirement. GENERAL CHARACTERISTICS OF S TYPE TEMPERATURE SENSORS RESISTANCE/TEMPERATURE TABLES Resistance at C Temperature Coefficient Temperature ( C) R R 1K Resistance in Ohms Complete Tables in 1 C or 1 F are available from our Technical Sales department RESISTANCE CHARACTERISTICS 1K The principle of temperature measurement of Pt-RTD Sensor is based on the measurement of electrical resistance. The resistance of Pt- RTD sensors vary with temperature almost linear in a precisely predetermined relationship. The relationship between temperature and resistance can be expressed exactly by a mathematical equation by which the principle values of the Pt-RTD resistors can be calculated as: R T = R O (1+aT-bT 2 -ct 3 (T-1) For Resistance/Temperature Table see above where, R T = Resistance at temperature T R O = Resistance at temperature C T = Ambient temperature ( C) a,b,c = Temperature coefficient Pt-RTD TCR = 375ppm/ C Temperature R () a b c T< C x x x1-12 T C x x1-7. Pt-RTD TCR = ppm/ C R () a b c 1, 5, x x x1-12 1, 5, x x1-7. TEMPERATURE COEFFICIENT OF RESISTANCE TCR is a characteristic of resistance varying with temperature. It indicates the medium relative resistance change according to temperature change. The average resistance change per degree can be expressed as following: TCR = R - R 1 (1/ C) R x 1 where, R = resistance at C R 1 = resistance at 1 C We offer both TCR = ppm/ C and 375 ppm/ C for DIN 4376 and IEC 75 standards.

4 TYPE SA/SB/SC/SD SERIES (Page 4 of 5) GENERAL CHARACTERISTICS OF S TYPE TEMPERATURE SENSORS DEVIATION OF TEMPERATURE & RESISTANCE Pt-RTD Sensor can be categorised as class A, B and C based on resistance tolerance. The limit deviation of Pt-RTD Sensor is accordingly determined by temperature and resistance tolerance shown in the following Table and Figure (in accordance with DIN 4376 and IEC75). Class A B C Resistance Tolerance ±.6% ±.12% ±.24% Limit Deviation ( O C) ±(.15+.2ITI) ±(.3+.5ITI) ±(.6+.7ITI) T ( C) Limit values and deviations for measuring resistors (TCR = ppm/ C) Principle Value Pt-1 (ohm) Limit Deviations Pt-1 Class A ClassB Ohm C Ohm C ±.1 ±.25 ±.22 ±.6 ±.6 ±.15 ±.12 ±.2 ±.13 ±.35 ±.3 ±.8 ±.2 ±.55 ±.48 ±1.3 ±.27 ±.75 ±.64 ±1.8 ±.33 ±.95 ±.79 ±2.3 ±.38 ±1.15 ±.93 ±2.8 ±.43 ±1.35 ±1.6 ±3.3 SELF-HEATING EFFECT Heat energy is generated when an electric current (1) is applied through the Pt-RTD resistor. This effect might result in errors of temperature measurement. The effect can be minimised by keeping the test current as low as possible (~1mA). Self-heating effect is expressed as milliwatts per Centigrade as following: mw/ C = S(P 2 -P 1 ) R 2 -R 1 where, R 1 = resistance at the lower power dissipation R 2 = resistance at the higher power dissipation S = thermometer Sensitivity (dr/dt), at the respective temperature, / C P 1 = lower power dissipation, mw P 2 = higher power dissipation, mw THERMAL RESPONSE TIME The thermal response time (t 9 ) if the time Pt Sensors required to respond to 9% the change of temperature. The response time is the time period, t 2 -t 1, based against the following formula: HOW TO ORDER SC 12 6 COMMON PART SA - -5 to +5 C SC - -5 to +6 C SB - See Relevant Table SD - Probe Assembly RESISTANCE VALUE The first digits are Example significant figures of resistance value and the third 1K : 12 one denotes the number of 1K : 13 zeros following 1K : 14 6 : /A : /B 1 : /C 2 : /D TCR/TOLERANCE 7 : 375/A 3 : 375/B 4 : 375/C 5 : 375/D PACKAGING - Glass Coated 1 - Ceramic Tube 2 - TO92F 3 - Electric Wire Meggitt Electronic Components Ltd. Ohmic House, Westmead Industrial Estate, Swindon, Wilts. SN5 7US Telephone:(1793)48731 (Admin.) (1793) (Sales) sales@megelec.co.uk Fax:(1793) This publication is issued to provide outline information only and (unless specifically agreed to the contrary by the Company in writing) is not to form part of any order or be regarded as a representation relating to the products or service concerned. We reserve the right to alter without notice the specification, design, price or conditions of supply of any product or service. Whilst Meggitt Electronic Components products are of the very highest quality and reliability, all electronic components can occasionally be subject to failure. Where failure of a Meggitt Electronic Components product could result in life threatening consequences, then the circuit and application must be discussed with the Company. Such areas might include ECG, respiratory. and other medical and nuclear applications and any non fail safe applications circuit.

5 TYPE SA/SB/SC/SD SERIES (Page 5 of 5) S SERIES PTC TEMPERATURE DETECTOR TYPICAL APPLICATION CIRCUITS OVER TEMPERATURE PROTECTION SIGNAL CIRCUITS The deviation across input and output of an electronic circuit results from the tolerance of its components. To eliminate such deviation, a full series of Over-Temperature Protection (OTP) signal circuits exists. The OTP signal circuits are produced with hybrid technology that eliminates the component deviation to meet high precision requirement. There are two basic circuits for OTP application. (1) Fixed Temperature Enabled Circuit The Fixed Temperature Enabled Circuit is shown here. This integrates a precise voltage dividing resistor network, Pt-RTD and competitor. The output is open-collector type for more flexible application. (2) Fixed Temperature Enabled/Low-Temperature Disabled Circuit The following figure shows the Fixed-Temperature Enabled/Low-Temperature Disabled Circuit. This circuit is basically the Fixed- Temperature Enabled Circuit with a positive feedback resistor whose resistance is taken into account in the circuit calculation. Therefore, the output voltage is enabled at temperature T2 but will not be disabled until temperature drops to T1. Although named a "OTP Circuits", the above two circuits can be used not only in over-temperature protection but also in other applications depending on the products the customer requirements. Vo T2 T1 Temp. Meggitt Electronic Components Ltd. Ohmic House, Westmead Industrial Estate, Swindon, Wilts. SN5 7US Telephone:(1793)48731 (Admin.) (1793) (Sales) sales@megelec.co.uk Fax:(1793) This publication is issued to provide outline information only and (unless specifically agreed to the contrary by the Company in writing) is not to form part of any order or be regarded as a representation relating to the products or service concerned. We reserve the right to alter without notice the specification, design, price or conditions of supply of any product or service. Whilst Meggitt Electronic Components products are of the very highest quality and reliability, all electronic components can occasionally be subject to failure. Where failure of a Meggitt Electronic Components product could result in life threatening consequences, then the circuit and application must be discussed with the Company. Such areas might include ECG, respiratory. and other medical and nuclear applications and any non fail safe applications circuit.