
B-153
Comes with complete operator‘s manual. 
Metric Ranges Available - Consult Engineering
Ordering Example: PX921-1KGI, 1000 psi transducer, 4 to 20 mA output, PG9 cable gland 
and internal terminal block electrical connection with 1⁄2Male NPT pressure port, and PX921-R, 
receiver/retransmitter, $1095 + 875 = $1970.
$
1095
All Models
⻬ Silicon-on-Sapphire
Sensor Assures 
High Stability and 
Repeatability 
⻬ Low Power Radio
Transmitter Built-in with 
Range of 152 m (500')
⻬ High Accuracy 12 bit 
⻬ No License is Required 
⻬ IP65/NEMA 4 Stainless
Steel Body
⻬ Solid State Reliability 
⻬ High Shock and Vibration
Typical Applications 
⻬ Mechanical and Civil
Engineering Projects
⻬ Process Plants 
⻬ Production Test Facilities 
⻬ Water Resource
Management
⻬ Power Generation
PX921 Series
4-20 mA Output 
0-5 to 0-15,000 psi 
0-0.5 to 0-1000 bar
WIRELESS TRANSMITTER 
SILICON-ON-SAPPHIRE 
LONG TERM RELIABILITY
PX921-100GI, 
$1095. shown 
smaller than 
actual size. 
To Order 
(Specify Model Number)
RANGE (psig) MODEL NO. PRICE COMPATIBLE METERS
30 inHg to 0 PX921-30VACI $1095 DP41-E, DP25-E, DP24-E 
0 to 5  PX921-005GI 1095 DP41-E, DP25-E, DP24-E 
0 to 10  PX921-010GI 1095 DP41-E, DP25-E, DP24-E 
0 to 15  PX921-015GI 1095 DP41-E, DP25-E, DP24-E 
0 to 30  PX921-030GI 1095 DP41-E, DP25-E, DP24-E 
0 to 60 PX921-060GI 1095 DP41-E, DP25-E, DP24-E 
0 to 100  PX921-100GI 1095 DP41-E, DP25-E, DP24-E 
0 to 150  PX921-150GI 1095 DP41-E, DP25-E, DP24-E 
0 to 200  PX921-200GI 1095 DP41-E, DP25-E, DP24-E 
0 to 300  PX921-300GI 1095 DP41-E, DP25-E, DP24-E 
0 to 600  PX921-600GI 1095 DP41-E, DP25-E, DP24-E 
0 to 1K  PX921-1KGI 1095 DP41-E, DP25-E, DP24-E 
0 to 1.5K  PX921-1.5KGI 1095 DP41-E, DP25-E, DP24-E 
0 to 3K PX921-3KGI 1095 DP41-E, DP25-E, DP24-E 
0 to 6K  PX921-6KGI 1095 DP41-E, DP25-E, DP24-E 
0 to 10K  PX921-10KGI 1095 DP41-E, DP25-E, DP24-E 
0 to 15K  PX921-15KGI 1095 DP41-E, DP25-E, DP24-E
OMEGA’s PX921 Series wireless 
transmitters are designed for safe 
operation in tough industrial 
installation—without the need for 
hard wiring! The PX921 operates by 
radio telemetry. A low power RF 
transmitter safely transmits the 
signal up to 152 m (500') to a 
receiver / retransmitter where it is 
converted into a 4 to 20 mA signal.
Rugged stainless steel constructed 
and featuring S.O.S. technology 
with a custom IC amplifier give the 
PX921 series high stability, low drift 
and long life.
SOS construction uses very stable 
solid state silicon strain gages on a 
Sapphire carrier which is glass 
bonded to a titanium diaphragm. This 
combination provides a very durable
transducer which 
has excellent 
stability over a wide 
temperature range. 
Additionally, the 
titanium diaphragm 
and Stainless Steel 
wetted parts provide 
maximum durability 
and corrosion 
resistance to harsh 
industrial chemicals. 
To Order 
(Specify Model No.)
MODEL PRICE DESCRIPTION
PX921-R $875 Receiver/ 
(Required) retransmitter
Required Accessory
To Order 
(Specify Model No.)
MODEL PRICE DESCRIPTION
OP-6 $340 Reference Book: 
Fundamentals of 
Temperature, 
Pressure and Air 
Flow Measurement
Accessory
CUSTOM BUILT TO ORDER

B
SPECIALTY
PRESSURE TRANSDUCERS
B-154
SPECIFICATIONS
(PX921 TRANSDUCER)
Excitation: 
Internal Battery: 10.5 to 15 Vdc (not supplied) 
External Supply: 10.5 to 30 Vdc
Output: 
Local Test Voltage: 0.5 to 2.0 Vdc FS 
Data Transmission: Serial bit stream 
Data Speed: 4800/9600 baud
Accuracy:
Resolution: 12 bit ADC 
Linearity and Hysteresis: 0.3%
Sensing Element: 4 active-arm bridge using 
Silicon-on Sapphire thin-film elements
Operating Temp Range: 
-20° to 80°C (-4° to 176°F)
Compensated Temp Range:
0° to 80°C (32° to 176°F)
Thermal Effects:
(Over the compensated range) 
Span: ±0.03% FS/°C 
Zero: ±0.02% FS/°C 
Proof Pressure:
1.5 times rated pressure will not cause changes 
in performance beyond the specified tolerance
Wetted Parts:
17-4 PH and 304 Stainless Steel and 
Titanium Diaphragm
Body: 300 Series Stainless Steel, sealed to 
IP65 (NEMA 4)
Electrical Connection:
Internal Screw Terminals via gland
Pressure Port: 
1
⁄2 NPT Male 
Weight: 1.2 kg (2.65 lb) maximum
(PX921 RECEIVER)
Input:
Data Transmission: Serial bit stream from PX921 
Data Speed: 4800/9600 baud
Output:
Analog: 4 to 20 mA dc 
Load Driving: 1500Ω maximum
Accuracy:
Resolution: 12 bit DAC 
Linearity and Hysteresis: ±0.3% FS
Body: Polycarbonate enclosure sealed to IP65 (NEMA 4X) 
Excitation: 10.5 to 30 Vdc 
UHF Radio Transmitter/Receiver:
Carrier Frequency: 418 mHz 
Modulation Type: FM
OPERATION:
The PX921 pressure transmitter converts pressure 
measurements to a digital code which is processes by the 
onboard microcontroller. The microcontroller generates a 
coded data frame in accordance with the protocol. This frame 
is then transmitted by UHF to the PX921-R where it is 
decoded, validated and converted to an analog 4 to 20 mA 
signal. This signal can then be transmitted and interface with 
all standard 20 mA loop instruments.
DATA TRANSMISSION:
Data is transmitted as a bit stream data frame using 
asynchronous protocol. a random delay between 
transmissions minimizes collisions between adjacent streams. 
Data error detection is employed to allow error free operation 
in high interference environments. Indication of receipt of 
uncorrupted data is provided on the PX921-R unit.
RADIO LICENSE:
No license is required with this equipment. 
Data transmission is via a radio transmitter operating at a 
designated low power UHF telemetry frequency. It operates in 
the 418 MHz region @ 0.25 mW.
INSTALLATION:
The PX921 is simple to install and does not require additional 
configuration tools. Once the PX921 has been connected to 
the process fitting, configuration is easily carried out by setting 
a series of miniature switches which are under the cover of 
the transducer. At this stage it is possible to check the 
calibration of the unit locally by measuring the voltage across 
tow test points, which can then be adjusted with the zero and 
span trimmers if required.
POWER SUPPLY
Units may be powered by either an internal battery (10.5 to 
15 Vdc) or by an external supply voltage (10.5 to 30 Vdc). In 
battery mode, a duty cycle power saving system is employed 
to extend battery life. 
WIRELESS TRANSMITTER 
SILICON-ON SAPPHIRE TECHNOLOGY
PX921 TRANSMITTER
DIMENSIONS: mm (inches)
120
(4.728)
200
(7.88)
75
(2.955)
60 
(2.364)
ANTENNA
SCREW CAP FOR EASE OF 
ACCESS FOR ZERO + SPAN 
ADJUSTMENTS
418MHz FM TRANSMITTER
ROBUST STAINLESS STEEL 
HOUSING TO IP65
STATE OF THE ART ANALOG 
AND DIGITAL ELECTRONICS
LATEST SILICON ON SAPPHIRE 
SENSOR DIAPHRAGM TECHNOLOGY
1/2'' NPTM
FIXING CENTERS
188 (7) X 89 (3.5)
CABLE 
GLAND
136 
(5.3584)
20
(0.788)
PX921 RECEIVER

One Omega Drive | Stamford, CT 06907 |  1-888-TC-OMEGA (1-888-826-6342) |  info@omega.com 
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