Temperature Sensors HEL-775 Series FUNCTIONAL BEHAVIOR RT = R0(1+AT+BT2-100CT3+CT4) RT = Resistance (W) at temperature T (°C) R0 = Resistance (W) at 0°C T = Temperature in °C B = -a d CT<0 =-a b A=a+ad 100 1002 1004 ACCURACY VS TEMPERATURE EL-700 platinum RTDs are available in two base resistance trim tolerances: ±0.2% or ±0.1%. The corresponding resistance interchangeability and temperature accuracy for these tolerances are: Trim Tolerance CONSTANTS -1 Alpha, α (°C ) Delta, δ (°C) ∗ Beta, β (°C) −1 A (°C ) B (°C−2 ) −4 ∗ C (°C ) 0.003750 ±0.000029 1.605 ± 0.009 0.16 3.81x10-3 -6.02x10-7 -12 -6.0x10 PLATINUM RTDs 0.003850 ±0.000010 1.4999 ± 0.007 0.10863 3.908x10-3 -5.775x10-7 -12 -4.183x10 ∗ Both β = 0 and C = 0 for T > 0°C CAUTION PRODUCT DAMAGE The inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD-induced damage and/or degradation, take normal ESD precautions when handling this product. Standard ±0.2% Temperature (°C) Optional ±0.1% ±∆R ±∆T ±∆R ±∆T (Ω) (°C) (Ω) (°C) -200 6.8 1.6 5.1 1.2 -100 2.9 0.8 2.4 0.6 0 2.0 0.5 1.0 0.3 100 2.9 0.8 2.2 0.6 200 5.6 1.6 4.3 1.2 300 8.2 2.4 6.2 1.8 400 11.0 3.2 8.3 2.5 500 12.5 4.0 9.6 3.0 600 15.1 4.8 10.4 3.3 MOUNTING DIMENSIONS (for reference only) mm/in HEL-775-A HEL-775-B 3,81 0.15 5,1 0.20 2,54 0.10 1 0,64 0.025 2,54 0.10 MAX. 12,7 0.50 MIN. 0,25 REF. 0.01 1 PROTECTIVE SEALANT MICRO SWITCH Sensing and Control Temperature Sensors HEL-775 Series PLATINUM RTDs ELECTRICAL INTERFACING Fig. 1 illustrates the most common method of measuring an RTD. As RT increases or decreases with temperature, Vo increases or decreases. An opamp is used to observe Vo. Lead wire resistance, L1 and L2, add to the RTD leg of the bridge and may affect the temperature reading. Fig. 2 is a simple circuit that provides a voltage output linear to within 0.1% or a ±0.3°C (0.5°F) error over a range of -40°C to +150°C (-40°F to +302°F). Fig. 3 illustrates one way to detect one particular temperature, if required in an application. The potentiometer may be adjusted to correspond to the desired temperature. RESISTANCE VS TEMPERATURE CURVE Fig. 1: Wheatstone Bridge 2-Wire Interface +Vs L1 R1 RT V o L2 R2 R3 Fig. 2: Linear Output Voltage +Vs +10V 10K 9K + - 10K +Vs V =IV R + - 10K -Vs 1K Vo=.001R T RT -Vs 1K 10K Fig. 3: Adjustable Point (Comparator) Interface Vs=5V 2K 2K 5K RT 2K + - Vo 2K 2 Honeywell MICRO SWITCH Division For application help, call 1-800-537-6945 Temperature Sensors HEL-775 Series PLATINUM RTDs WARRANTY and REMEDY Honeywell warrants goods of its manufacture as being free of defective materials and faulty workmanship. Contact your local sales office for warranty information.If warranted goods are returned to Honeywell during the period of coverage, Honeywell will repair or replace without charge those items it finds defective. The foregoing is Buyers sole remedy and is in lieu of all other warranties, expressed or implied, including those of merchantability and fitness for a particular purpose. Specifications may change at any time without notice. The information we supply is believed to be accurate and reliable as of this printing. However, we assume no responsibility for its use. While we provide application assistance, personally, through our literature and the Honeywell website, it is up to the customer to determine the suitability of the product in the application. For application assistance, current specifications, or name of the nearest Authorized Distributor, contact a nearby sales office. Or call: 1-800-537-6945 USA 1-800-737-3360 Canada 1-815-235-6847 International FAX 1-815-235-6545 INTERNET www.honeywell.com/sensing [email protected] MICRO SWITCH Honeywell Inc. 11 West Spring Street Freeport, Illinois 61032 Printed with Soy Ink on 50% Recycled Paper For application help, call 1-800-537-6945 Honeywell MICRO SWITCH Division 3