The Teledyne Hastings Instruments HVG-PR Pirani Vacuum Gauge was designed specifically to address these challenges. With two possible analog output curves, an industry-friendly RJ45 connection with standardized power / analog signal pinouts, and a compact size, the HVG-PR makes gauge replacement faster, easier, and more cost-effective than traditional alternatives.
Does My New Gauge Have the Correct Analog Output Signal?
A common issue encountered during vacuum gauge replacement is analog output incompatibility. Pirani vacuum gauges use manufacturer-specific voltage-versus-pressure relationships.
When a replacement gauge uses a different output signal than the original device, the consequences can include:
In many cases, the engineering effort required to accommodate a new gauge can cost far more than the gauge itself.
However, most major pirani vacuum gauge manufacturers use one of two basic logarithmic output signal scales: 1.0 V/decade or 1.286 V/decade. Fortunately, the HVG-PR supports both! The end-user can easily select which analog output signal they need.
| Output | @ 0.0001 Torr | @ 1,000 Torr |
P (Torr) from |
Volts from P (Torr) |
| 1.00 V/decade | 2.0000 V | 9.0000 V | P = 10(V-6) | V = log10P + 6 |
| 1.286 V/decade | 1.1600 V | 10.1620 V | P = 100.778(V-6.304) | V = 1.286log10P + 6.304 |
By selecting the output mode that matches the existing installation, the HVG-PR can often replace the original Pirani gauge without requiring any changes to the control software or pressure conversion algorithms already running in the system.
Do I Need to Rewire...And Can I Use my Existing Power Source?
Another challenge in vacuum equipment design is wiring. Large vacuum systems can contain multiple gauges, and each can require dedicated cables and specialized connectors. This increases assembly time, cable complexity, and material costs.
Most major pirani gauge manufacturers either offer or standardize on the RJ45 connector. Also, most major pirani vacuum gauge manufacturers standardize on the four most essential pins for this connection: Power, Power Common, Analog Output Signal, and Analog Common. If your vacuum equipment only uses the Analog Output Signal from the pirani vacuum gauge (and it uses RJ45), you probably will not have to rewire. Check your gauge RJ45 pinout for pins 1, 2, 3, and 5 as seen in the pinout chart. If they are the same, you don’t need to rewire.
Also, the most common DC Power Source for vacuum instrumentation is 24 VDC. The HVG-PR is flexible and will work with any power source from 12 to 36 VDC.
Will the HVG-PR Physically Fit in my Application?
The HVG-PR offers a compact design which is ideal for OEM enclosures and other tight spaces. Two mechanical connections are offered: KF-16 and 1/8” male NPT.
A Simple Four-Step Replacement Process
Determine whether the original gauge uses a 1.0 V/decade or 1.286 V/decade output curve. This information is typically found in the vacuum gauge manual or the PLC scaling equations.
Verify that your power source is between 12 and 36 VDC.
Confirm that your vacuum connection is compatible with either KF-16 or 1/8” NPT. Make sure to order the correct one.
Install the HVG-PR and connect the electrical interface. If you are only using the analog output signal for your system and currently use an RJ45 with the same connections on pins 1, 2, 3, and 5, you can plug and go. Otherwise, the use of a standard RJ45 connector allows for a quick connector conversion.
Please see the HVG-PR product manual instructions to quickly select the output signal you require. 1.0 V/decade is the default, so you only need to make a change if you are using 1.286 V/decade.
Since the output curve matches the existing control logic, the system can often return to service without rewriting pressure conversion equations, modifying PLC code, or reconfiguring HMI displays.
An Ideal Upgrade for OEMs and Maintenance Teams
The HVG-PR was designed with practical field requirements in mind. Rather than forcing users to adapt their equipment around the gauge, the gauge adapts to existing equipment through:
For OEMs and system integrators looking to reduce assembly costs and maintenance departments seeking faster replacements, the HVG-PR offers a straightforward path to modernizing vacuum measurement systems without major redesign efforts.
Visit https://www.teledyne-hi.com/en-us/what-we-do/hvg-pr to learn more about the HVG-PR vacuum gauge.
Visit https://www.inforad.co.kr to learn more about Inforad’s complete sales, service, and design / build capabilities for Teledyne Hastings Instruments’ vacuum gauges, mass flow meters, and mass flow controllers in South Korea.
If you have questions about vacuum gauges or vacuum controllers, feel free to contact us by phone (+1-757-723-6531 or 1-800-950-2468), email Hastings_Instruments@Teledyne.com, or via Live Chat on our website www.teledyne-hi.com.