SCX100DN SENSYM, SCX100DN Datasheet - Page 8

• Manufacturer Part Number: SCX100DN
• Description: PRESSURE SENSOR, 0-100PSID
• Manufacturer: SENSYM

Specifications of SCX100DN

• External Depth: 26.2mm
• External Length / Height: 25.4mm
• External Width: 27.9mm
• Fixing Centres: 21.6mm
• Hysteresis: 1%
• Lead Spacing: 2.54mm
• Linearity: 1%
• Operating Pressure Range: 0 To 100psid

SCX Series
Precision compensated pressure sensors
PRESSURE SWITCH
The circuit shown in Figure F is an example of using the SCX01D
to make an accurate 0.5 psi switch. This design can be easily
adapted to other pressure ranges by using higher pressure range
SCX sensors.
Circuit description
Operating the SCX01D from 5V the sensor will have
sensitivity given on the SCX data sheet. The output at 0.5 psi will
be 3.75 mV. Resistor R
D
pressure and amplifier A
pressure from 0 to 1 psi. Resistors R
hysteresis to comparator A
movins input signals. R
Care must be taken when laying out the comparator circuit; lead
lengths should be as short as possible.
Adjustment procedure
Apply 0.5 psi and adjust R
high state (4.3 V) to a low state (0.0 V).
8/10
1
biases the amplifier output voltage to 1.2 V with zero input
11
4
2
sets the amplifier gain to 269 V/V. Zener
sets the switch point for the comparator.
swings from 1.2 V to 3.2 V for an input
11
3
to ensure clean transitions for slow
until the output just switches from a
7
and R
8
provide 5 mV of
Figure E. Timing diagram
5
/
12
the
PORTABLE PRESSURE METER
The circuit shown in Figure G is a 0 to 200 millibar portable pressure
meter. The 3
circuit operates from a single 9 V battery and draws approximately
4.5 mA supply current. This will provide a typical battery life in excess
of 100 hours. The minimum battery voltage is approximately 6.5 V.
This meter provides resolution to 0.1 millibars. The same circuit
can also be used for other pressure ranges simply by changing the
sensor and gain.
Circuit description
The LM10CN (A
power the SCX05DN, amplifier A
a high input impedance diff-in,
diff-out amplifier. The sensor output is amplified to 200 mV full-
scale for the A/D input. R
shown. The gain equation is:
R
adjustment. The voltage from pin 35 to pin 36 is approximately 100
mV when the display reads 199.9 millibar.
Component selection
The value of the components R
for 200 mV full-scale (see the Intersil ICL7106 datasheet). R
R
C
and auto zero capacitors can be polystrene or mylar, the clock
capacitor, C
Adjustment procedure
Apply 195 millibar to the meter and adjust R
195.0. Apply 0 psig and adjust R
Repeat if required.
4
8
3
should be 15 turn cermet pots, R
the integrating capacitor should be polypropylene, the reference
is the zero adjust pot and R
4
, is mica.
1
/
2
A
digit display will read 199.9 millibar full-scale. This
1
) is used to generate a regulated 5 V supply to
V
= 2 (1 +
www.sensortechnics.com
5
R1
sets the gain to 14V/V for the values
/
R5
6
-R
)
2
, and the ICL7106 Amplifier A
10
8
4
6
-R
and C
until the display reads 000.0.
provides the full-scale span
10
are metal film 1% resistors.
1
-C
8
5
until the display reads
have been optimized
August 2005 / 053
4
and
2
is