Advantages General Description
􄤎Micro-processor based digital
differential pressure switch/transmitter
for industrial applications
􄤎Adjustable switch points allow the user
to obtain various pressure settings for
each of the 2 switches and span
􄤎Measuring ranges from 0.1 to
35kgf/cm2
􄤎Advanced piezoresistive silicon
measuring cell
􄤎Excellent accuracy and long term
stability
􄤎4 digit LED local display
􄤎2 switching points with analog output
signal
􄤎Measuring range turn down maximum
10 : 1
Applications
The high precision micro-processor based
digital differential pressure switch with
analog output signal can be used for a
wide range of applications in process
control, automatic machinery and
hydraulic or pneumatic
system design.
􄤎Chemical, petrochemical, food and
drug process controls
􄤎Hydraulic and pneumatic equipments
􄤎Machine tools and automatic
machinery
􄤎LPG and LNG transmission control and
storage tank monitoring
􄤎Engine monitoring and control
􄤎Vacuum pump and injection molding
machine
􄤎Powered DC or AC(optional)

P929 series micro-processor based digital differential
pressure switch uses two matched piezoresistive silicon
measuring chips, offering high stability and performance
with true wet/wet operation, suitable for measuring
differential pressure of gases and liquids compatible with
stainless steel. The 929, with its built-in piezoresistive
pressure measuring chip, a 4-digit digital display, 2
switching points, 4~20mA analog output signal and a
front function keys, offers the user all the advantages of a
modern electronic pressure measurement. External
adjustments allow the user to set the pressure ranges,
switch points, deadbａnd and zero or span calibration,
etc.
It has a water resistant, explosion-proofed for complete
protection from harsh environment and its 4~20mA
current output is ideal for remote monitoring of both
primary and secondary process variables. It is extremely
versatile and suitable for measuring dynamic and static
pressure. The pressure to be measured acts through thin
corrosion resistant stainless steel 316L diaphragm on a
silicon measuring element. The pressure transmitting
medium is silicon oil. The measuring element contains
diffused piezoresistive resistors which are connected into
a Wheatstone bridge. The output signal of this bridge is
temperature compensated and converted into a
standardized current or voltage output signal.

Technology Piezoresistive silicon pressure sensor
Pressure ranges 0~0.1 to 35kgf/cm2
Pressure reference Differential pressure
Overload 3 ×full scale without damage
Output Signal 2 switching points
4~20mA current output
2 switching points with analog output (4~20mA)
Other signals available on request
Local display LED 4 digit
Electrical connection type Terminal head with Ex-protection
Excitation voltage 24V DC or 85~260V AC (option)
Load resistance max@24V 500Ω at 24V
Influence of excitation 0.01% FSO/V
Power ripple ≤500mV P-P
Reverse polarity Protected
Shock resistance No change in performance after 10Gs for 11ms
Vibration 0.1G (1 m/s/s) maximum
Response time(10~90%) ≤2 milliseconds
Switching current Maximum 1.2A
Range turn down Maximum 10 : 1
Accuracy ≤±0.3% FSO
Non-linearity ±0.99% FSO typical
Repeatability ±0.015% FSO typical
Pressure hysteresis ±0.010% FSO typical
Long term stability ±0.3% FSO over 6 month
Cutoff frequency(-3 d B) ≤2kHz
Reference temperature 35°C
Operating temperature range -40~125°C
Compensated temperature range 0~82°C
Thermal sensitivity shift ≤±0.2%FSO in reference to 35°C typical
Thermal zero shift ≤±0.2% FSO in reference to 35°C typical
Thermal hysteresis ≤±0.1% FSO in reference to 35°C typical
Process connection PT1/4″female thread(standard)
Other connections available on request
Electrical connection PT1/2″female
Process media Gases and liquids compatible with stainless steel 316
Materials wetted by process Diaphragm : Stainless steel 316L
Housing : Aluminum die-casting terminal head
Gasket O-ring : Viton (HNBR, CSM, etc.)
Enclosure rating IP65
Explosion protection Ex d IIC T6
Influence of mounting position Not critical.
Weight Approx. 1700g
Options Mounting bracket
Remote sealed diaphragm
Note : ① If it is installed in explosive atomosphere, the covers should be kept tight when circuit alive.