Specifications SPD series Version 1.0 SPD series Performance Characteristic at Vcc =5V excitation @ 25 ° C. Parameter Min Typ Max Units. Excitation Voltage Excitation Current Offset 0 0 -50 5 1.5 0 10 3.0 50 Volts mA mV Temp Coeff Span -27 -22 -17 %FS/100°°C Temp Coeff Offset Temp Coeff Resistance -7 23 28 +7 33 %FS/100°°C %FS/100°°C Linearity Hysteresis -0.3 ± 0.1 +0.3 0.15 %FS % of Range ± 0.2 ± 0.5 1 Repeatability ) Response time (10-90%) 1 Bridge resistance Pressure overload 2.7 Operating temperature Storage temperature -20 -30 1 FSO ms 3.3 4.0 1.35 KΩ Bar 85 125 °C °C ) measured after 1,000 temp. cycles 0 – 70 °C, 10 pressure cycles (10-90% FS) 6 Type Range (Bar) Min Typ(FS) Max Unit 005G 015G 030G 100G 100 140 160 190 130 175 200 240 mV mV mV mV 0000- 0.350 1 2 6.5 70 100 120 120 1 Pa = 0.145. 10 –3 PSI or 1 PSI = 6.89476*103 Pa 1 Bar = 10 5 Pa = 105 N/m2 Understanding the specifications The available range of SPD series pressure sensors allows for a wide range of applications. In order to get good results, it is very important to fully understand the meaning of the various specifications and their effects on accuracy, especially the ones that deal with temperature coefficients. (Silicon resistors are very temperature dependent). -2 – SMARTEC BV, Delpratsingel 26 4811 AP Breda, The Netherlands WWW.SMARTEC.NL Tel: +31 76 5205353 Specifications SPD series Version 1.0 Excitation voltage The excitation of the sensor can be AC or DC. Specifications are given with a DC excitation of 5V. In order to avoid electrical breakdown it is advised not to exceed the maximum values given. Offset The offset value is the electrical output voltage (imbalance) of the pressure sensor when zero pressure is applied. The offset value for the absolute type is determined by extrapolating the measured values at two different pressures (atmospheric air and 0.05 Bar). The pressure in reference chamber is about 25 mTorr (3.33 Pa). Temperature coefficients Silicon resistors are very temperature dependent. The overall drift of the resistors is not of interest to most users (The bridge resistors are located on the same die). The temperature coefficients of the offset and span, however, are very important. All the temperature coefficients are given in percentage of full-scale range (FS) and over a temperature range of 100 °C. The maximum value of the temperature coefficient of the span is minus 27%, which means that worst case the span becomes 27% smaller over the full temperature range of 100 °C. The offset will vary no more than ±7% of the span over the same temperature range. Calculation example (please refer to the parameter table above) Suppose the use of a pressure sensor of type SPD 015G over a temperature range of 100 °C. The typical full scale span is 140 mV. The offset (at a fixed temperature) will be between -50 and +50 mV. Offset When the static part of the offset has been nulled, the offset can still vary ±7% of 140 mV (± 9.8 mV), over the temperature range of 100°C. Span The typical full-scale span is 140 mV and the typical temperature coefficient of the span equals –22 %FS/100 °C. Typically, you would therefore have a span, which varies between 140 mV and 109 mV (140 mV minus 22%), over the full temperature range of 100 °C. -3 – SMARTEC BV, Delpratsingel 26 4811 AP Breda, The Netherlands WWW.SMARTEC.NL Tel: +31 76 5205353 Specifications SPD series Version 1.0 In the worst case scenario the minimum value of the span is 100 mV, which means that the sensor has a span of 100 mV, which could drop to 63mV (100 minus 27%) over the full temperature range of 100 °C. Linearity The linearity is defined as the maximum deviation from the best fitted straight line. Outline drawings and dimensions. 4 out + 6 12 5 5 exc 0.5C- ∅ ∅3 4 R=1 pressure port ( ∅ ∅ 0.8) 1 out - 4 2.8 14 8 6.8 2.54(2x) vent hole ∅ ∅ 0.8 1 2 3 2 exc Gauge type sensor Connection diagram (Top View) 0.5 0.25 11±0.5 7 4 0.15±0.1 3.5 Atmospheric Pressure inlet @bottom 0.8±0.2 2.54 7 Absolute type sensor 1 All sizes in mm. Wetted materials: glass, ryton, silicon, fluorosilicon and gold Other encapsulations on request. Ordering information Part no. Pressure range SPD005G SPD015G SPD030G SPD100G SPD015A 0 – 0.35 Bar (Gauge) 0 – 1.0 Bar 0 – 2.0 Bar 0 – 6.5 Bar 0 – 1.0 Bar (Absolute) -4 – SMARTEC BV, Delpratsingel 26 4811 AP Breda, The Netherlands WWW.SMARTEC.NL Tel: +31 76 5205353