Frequently Asked Questions
Getting Started
First, make a list of what range of vacuum you are interested in, with the necessary and or “nice to have” features such as data out and relay controls. Then call us! 732-765-0900.
Our best seller for this application is the Model 100H. This device includes a Hastings DV-6M thermocouple vacuum gauge tube, which is commonly found permanently installed on cryogenic vacuum jacketed pipes and vessels. This gauge is often purchased with a carrying case to facilitate mobile use.
The Bullseye Precision Gauge is a popular choice. A rubber stopper can be installed on the gauge tube itself, and this assembly is put on the vacuum pump to test its ultimate suction. The Bullseye is a wide range rough gauge that will measure from 760 Torr (ATM) all the way down to 1 millitorr, allowing you to troubleshoot leaky valves and connections. No other products that employ thermocouple gauge technology can do this.
We have many output schemes that will seamlessly integrate with your computer or PLC. We offer digital RS232, an analog output voltage corresponding to pressure (often called recorder out), Bluetooth data collection using the DigiVac app, and real-time vacuum measurement and graphing via WiFi connection to vacuumnetwork.org. Contact our technical support team to determine which option is best for you.
Most of our gauges read in Torr, where the minimum vacuum reading is .001 Torr or 1 millitorr. Any thermocouple gauges including the Model 200, 100H, 215 and certain varieties of the StrataVac will read .001 at the low pressure end of the range. These same gauges enable you to read up to 760 Torr (ATM) which will identify potential problems such as leaky valves and connections. Consult the Conversion Table for a table that compares millitorr, Torr and other pressure units commonly used in vacuum.
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Model 200s are a stock gauge, and can typically be sent the same day if the order is phoned in by 1pm.
Yes. – Everything can be shipped to arrive first thing next day.
Most of our gauges read in Torr, where the minimum vacuum reading is .001 Torr or 1 millitorr. Any thermocouple gauges including the model 200, 100V, 100H, 215 and 201 will read .001 at the low pressure end of the range. These same gauges enable you to read up to 760 Torr (ATM) which will identify potential problems such as leaky valves and connections. No other products that employ thermocouple gauge technology can do this.
Consult the Conversion Table for a table that compares millitorr, Torr and other pressure units commonly used in vacuum. (https://www.digivac.com/tech-info/conversion-table/)
Credit card (Visa, MasterCard, and American Express), pre-approved company check, PayPal, Google checkout, and Bank funds transfer. The website allows credit card, PayPal and net30 when an approved account exists.
Staying Up and Running
This depends on how your gauge is used, the contamination levels in your process, and how long it's been since your last calibration. We recommend calibration once per year for clean, dry environments; more often for instruments exposed to a lot of process contaminants. New gauges are calibrated in our factory and are ready to use; they do not require calibration by the user.
Many of our gauges are designed to replace popular gauges that are used in laboratory and manufacturing equipment. For example, our 801W and DVG-6 are redesigned drop-in replacements for the original gauges of the same name.
We can likely repair any old DigiVac vacuum gauge. They are made from solid state electronics and are very robust. Call us at 732-765-0900 to obtain a Return Materials Authorization number. Once the unit is reviewed we will call you with an estimate for the repair before any work is performed.
Each instrument is calibrated to its specific sensor, and replacing the sensor means the gauge must be re-calibrated. We can provide calibration in our facility, or send field calibration instructions to you depending on the instrument.
Instruments returned for repair or calibration need an RMA number and a completed contamination form. Call us at 732-765-0900 to obtain an RMA number. More details can be viewed at our Returns and Services Inquiry page.
Advanced Technical Requirements
Do not use thermocouple technology to measure explosive gasses. Thermocouple wire filaments can exceed 400 degrees Celsius. To measure vacuum for explosive gasses and isolated transducer should be used and potentially additional casing depending what environmental requirements exists… for example Class 1 Div 2.
Most of our gauges do just fine in a gas vapor, such as those found in distillations. Thermocouple technology tends to be quite inexpensive and rugged. For particularly messy installations, we offer a "siphon tube" to mount between your process and the thermocouple gauge tube to reduce the possibility of contamination.
A NIST calibration is the method and resulting documentation for an instrument calibrated against a NIST standard instrument where accuracy data is written down to identify traceability back to the National Institute of Standards and Technology (NIST) in Gaithersburg, MD. Note all vacuum instruments that leave the DigiVac factory are calibrated under real vacuum against a NIST standard. The only difference between a NIST calibration and a standard DigiVac calibration that is included on all instruments is the inclusion of a paper certificate that identifies the instrument calibration traceable back to NIST standards.
Thermocouple instruments are at their most accurate from .001 Torr to 5 Torr. See our DigiVac Accuracy page for up-to-date specs for each instrument.
We have a wide range of instruments with valves that can be used to control vacuum to precise levels. Please contact us for more information on the correct configuration.
There could be several reasons for this. First, different technologies react differently to change in vacuum, and some indirect measurement methods (like Pirani, convection and thermocouple) tend to exhibit a hysteresis affect. A capacitance manometer will respond differently than a thermocouple for example. Also, one or more of the sensors may be contaminated which may reflect accuracy. One or of the devices may be placed in a different part of the vacuum system that may have a slightly different pressure, or be closer to a leak or source of vacuum. And of course something might be broken. We can help troubleshoot, give us a call.
Yes. We recommend regular sensor cleaning for instruments used in processes with high degrees of contamination. You can find comprehensive sensor cleaning instructions.
https://www.digivac.com/wp-content/uploads/2020/08/Sensor-Cleaning-Steps-for-Success.pdf
See our Repairs and Troubleshooting page for comprehensive information on commonly-observed issues with our vacuum gauges.
The 4 pins on the top of the sensor are electrically connected inside by two thin filaments welded together inside the sensor body. We use the circuitry of our gauges to heat one of those filaments, then that wire will heat or cool in proportion to the amount of gas bombarding it. More air molecules around the filament will transfer heat away, while fewer molecules to diffuse the heat will keep the wire hotter. Then the other filament takes the first one’s temperature, and our software interprets a change in temperature as an equivalent change in pressure, turning it into a reading anyone can understand.
NIST calibrations and repairs have an approximate 2-week lead time, though most are sent back to the customer within a week of receipt. Give us a call for up-to-date lead times. Expedited calibrations and repairs are available at a cost of $40 per instrument, which will be repaired or calibrated and sent back the same day we receive it.
Yes. Please contact us for pricing and rental options.
Field calibration is possible for some gauges, but we recommend gauges be returned to DigiVac for factory calibration. Most gauge calibration procedures require a clean and leak-free vacuum system capable of achieving pressures as low as 1 millitorr, and another vacuum gauge (whose stated accuracy is better than the unit you'd like to calibrate) whose readings you trust to use as a standard. We can provide emergency field calibration instructions for customers who feel confident in performing the calibration on their own.
DigiVac is classified as an essential business due to manufacturing instruments used in industries such as electrical maintenance, aviation and medical device production/testing, and has remained open consistently through the pandemic. Our employees are temperature-checked daily and wear masks in our facility. Most employees work from home at least one day a week, and our 8,400 square-foot facility combined with a small staff makes it easy to maintain distancing.
