yellow jacket eVac Pro User manual

Operation and Maintenance Manual
eVac™ Pro Programmable
Digital Vacuum Gauge

Introduction
Thank you for your purchase of the YELLOW JACKET® eVac Pro Digital Vacuum
Gauge. With the eVac Pro, you can accurately measure vacuum pressure in Microns,
Pascals, Millibar, Millitorr, mmHg, PSI, and inHg with resolution down to 0.1 micron.
Ideal for the HVAC/R, industrial, and scientific professionals, the eVac Pro is small,
lightweight, rugged and easy to use. It is programmable, allowing for unattended
evacuation and rise-time testing of HVAC/R systems of all sizes.
Features
Large, high-visibility back-lit LCD display
Measures Vacuum in Microns, Pascals, Millibar, Millitorr, mmHg, PSI, and inHg
0 to 25,000 Micron range with 0.1 micron resolution less than 10,000 microns
“Analog” vacuum level bar graph
Evacuation progress indicator shows vacuum between 25,000 microns and ATM
Vacuum leak rate, ambient temperature, and saturation temperature indicator
Automatic oil sensor
Measures ambient and saturation temperature in Fahrenheit and Celsius to 0.1˚
Built-in memory retains all previous settings
Rugged, compact design (protective silicone rubber boot available)
Long battery life
Programmable automatic evacuation and rise-time testing
Calibration Self Test -- can be field calibrated with no special equipment
Ideal for HVAC/R service, industrial use, and scientific measurement
Specifications
Range: 0 – 25,000 Microns (3333.1 Pa, 33.331 mBar, 25,000
mTorr, 25.000 mmHg, 0.4 8341 PSI,
-28.037 inHg)
Vacuum Accuracy: 5% of Reading +/- 5 Microns
Vacuum Resolution: 0.1 Micron (@ 0.0 to 9999.9 Microns)
Temperature Accuracy: 0.2˚F (0.1˚C)
Temperature Resolution: 0.1˚
Warm-up Time: Instant
Response Time: Instant
Power: 9V Alkaline Battery
(9V Lithium recommended for low temperature operation)
Battery Life: Up to 300 Hours
Operating Temperature: 10˚F – 122˚F (-12˚C – 50˚C)
Vacuum Port Fitting: ¼” Male Flare – nickel plated for durability with dust cap
Maximum Overpressure 500 PSI
Weight: 6 oz. (170g) including battery and swivel hook
Dimensions: 3.5” x 3” x 1.25” (9cm x 7.5cm x 3cm)
WARNING: To avoid personal injury and to prevent damage to the eVac Pro, never
exceed 500 PSI.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
2

Parts Diagram
3

LCD Display
4
Item Function
A
Main Numeric Display
B
Alternate Numeric Display
C
“Analog” Vacuum Level Bar Graph and Evacuation Progress Indicator
Backlight Indicator. Flashing: Temporary, Solid: Always On
Sound Indicator
Battery Level Indicator
Set Mode Indicator
Indicates Programmed Evacuation or Rise Time Analysis in Progress
Indicates Programmed Evacuation or Rise Time Analysis is Complete
Oil Sensor Indicator
Calibration Mode Indicator
Indicates that Evacuation Time is Displayed on the Alternate Numeric Display
Indicates that Rise Time is Displayed on the Alternate Numeric Display
Indicates that Ambient Temperature is Displayed on the Alternate Numeric Display
Indicates that Saturation Temperature is Displayed on the Alternate Numeric Display
Indicates that the Vacuum Leak Rate is Displayed on the Alternate Numeric Display
Indicates either Celsius or Fahrenheit Degrees are Displayed
Indicates that the Vacuum Leak Rate is Displayed in UNITS/second or UNITS/minute.
Pound per Square Inch Units Indicator
Inches of Mercury Units Indicator (Gauge Pressure Referenced to –29.921 inHg)
Pascal Units Indicator
Millibar Units Indicator
Millimeters of Mercury Units Indicator
Millitorr Units Indicator
Micron Units Indicator

Keypad
5
Item
Function
Press to Turn Power On.
Press and Hold to Turn Power Off.
While power is off, Press and Hold for Calibration Test.
Press and Release to Change Display Units.
Press and Hold to Change Temperature Display Units (
°
F or
°
C).
Press and Release to Start RUN Mode (Evacuation or Rise Time Analysis).
Press and Hold to Cancel RUN Mode .
Press to Switch Between Ambient Temperature, Leak Rate, and Saturation
Temperature on Alternate Display.
Upon Initiating RUN Mode, Press to switch between Evacuation and Rise Time
Analysis.
Press and Release to Activate Backlight.
Press or Press and Hold to Change Programmed Pressure or Time in SET Mode.
Press and Hold to Enter SET Mode.
Press and Release to Switch to Next Setting.
Press and Hold to Exit SET Mode.
Press and Hold to Mute/Un-mute Sound.
Quick Start
To operate the eVac Pro as a basic vacuum gauge:
1. Install the battery as described in the “Battery Installation” section below.
2. Turn the power on by pressing . The display will show to indicate
pressure greater than 25,000 Microns.
3. Select the desired units by repeatedly pressing .
4. Attach the eVac Pro to the system to be evacuated with a high quality vacuum
hose or brass coupler. Start the vacuum pump. Read the vacuum level from the
Main Display.
5. Turn the power off by pressing and holding .
WARNING: To avoid damaging the eVac Pro, only hand-tighten the sensor connec-
tion. If greater torque is required, support the sensor body with a ¾” wrench. Do not
use gauge body for leverage.
NOTE: To assist in the use of this gauge and the interpretation of vacuum information,
please refer to the Frequently Asked Questions Section at the end of this guide.

Battery Installation and Replacement
1. If installed, remove the protective boot.
2. Remove the battery cover from the rear of the eVac Pro by compressing tab
at the base of the battery cover.
3. If necessary, remove and detach old battery from battery clip.
4. Attach battery clip to new battery and insert into battery compartment.
Replace battery cover by aligning tab and snapping back into place.
5. Reinstall the protective boot.
IMPORTANT: TO PREVENT DAMAGE FROM LEAKING BATTERIES, DO NOT
LEAVE A DEAD BATTERY INSIDE THE eVac Pro. REMOVE BATTERY IF THE
eVac Pro IS NOT TO BE USED FOR AN EXTENDED PERIOD OF TIME.
Battery Level Indicator
The battery level indicator shows the relative strength of the battery. Four bars
indicate full power. As the battery is depleted, the number of bars displayed decreas-
es, until no bars are left. At this point, the battery must be replaced (refer to the
Battery Installation section above). If the battery power drops to the point where the
eVac Pro can no longer function accurately, the alarm will beep 10 times and the
power will turn off automatically. When the battery is replaced, and the eVac Pro is
turned back on, the eVac Pro will resume operation with all previous setting intact.
Units
Change the displayed units by pressing and releasing the key on the keypad.
The appropriate units indicator on the LCD display will cycle through PSI, inHg, Pa,
mBar, mTorr, mmHg, or Microns with each press. The units cannot be changed in
the Set Mode or the Run Mode (see corresponding sections below).
Hi-Pressure Indication
If the sensed vacuum pressure exceeds 25,000 Microns (0.48342 PSI, -28.937 inHg,
3333.1 Pa, 33.331 mBar, 25,000 mTorr, or 25.000 mmHg), the display will show .
Sleep Mode
Unlike other digital vacuum gauges, the eVac Pro helps to conserve battery life
through advanced power management. After 5 minutes of displaying , the eVac
Pro will enter Sleep Mode in which the sensor and backlight are turned off, thus
reducing the load on the battery and extending the battery life up to 300 hours or
more. While in this mode, the display will show . Approximately every 35
seconds, the gauge will automatically check the pressure and exit Sleep Mode if the
pressure is less than 25,000 Microns. The gauge can be manually brought out of
Sleep Mode by pressing any key on the keypad. While in Sleep, the gauge will beep
twice every 5 minutes to remind you that it is on. The eVac Pro will not sleep in the
Set Mode or the Calibration Mode (see the corresponding sections below).
Auto Power-Off
After 1 hour in “Sleep Mode” the eVac Pro will automatically turn itself off to further
conserve battery power. The eVac Pro will not auto power-off if an Evacuation or
Rise Time Test program is running.
6

Oil Sensor
It is necessary to prevent oil from being drawn into the vacuum sensor. For HVAC/R
service, always recover refrigerant prior to attaching the gauge. If possible, always
close the blank-off valve on the vacuum pump prior to turning the vacuum pump off.
Over time, oil vapor and other materials may contaminate the sensor. The eVac Pro
has a built in oil sensor that will detect this condition. If the indicator on the
display illuminates, this is an indication that the vacuum sensor has been contaminat-
ed and is no longer functioning accurately. If the sensor becomes completely
saturated with oil to the extent that it cannot function properly at all, the message
will show on the display. Prior to further use of the eVac Pro, clean the sensor as
describe in the “Cleaning the Vacuum Sensor” section below.
Backlight
To activate the backlight temporarily, press once. The indicator on the
display will flash, and the backlight will turn off automatically after 1 minute. To
activate the backlight permanently, press again. The indicator on the display
will show solid. Turn off the backlight by pressing repeatedly until the indicator
turns off. During Sleep Mode, the backlight will turn off to help conserve battery
power, but will turn on again automatically upon resumption of normal operation if it
was previously set in the permanent-on mode.
Sound
The eVac Pro has an internal speaker that will emit a beep for each valid key press,
and also functions as an alarm in the Programming and Calibration modes (see
corresponding sections below). It will also beep every 5 minutes in Sleep Mode. For
silent operation, pressing and holding the key will mute the sound. The alarm is not
affected by the mute status. The indicator on the LCD display indicates that the
sound is on (not muted).
Range and Resolution
The eVac Pro has a broad vacuum pressure measurement range, and the highest
resolution of any gauge. The display range and resolution depends upon the units
displayed and the vacuum pressure reading, according to the table below:
*NOTE: inHg is displayed as Gauge Pressure, referenced to a Standard Atmosphere (-29.921 inHg).
7
Units
Vacuum
Range
Vacuum Pressure
Reading
Resolution
PSI
0 — 0.48342 0 – 0.48342 0.00001 PSI
inHg*-29.921 — -28.937 -29.921 — -28.937 0.001 inHg
Pa 0 — 3,333.1
1,000.0 — 3,333.1
0.1 Pa
0 — 999.99
0.01 Pa
mBar 0 — 33.331
10.000 — 33.331
0.001 mBar
0 — 9.9999
0.0001 mBar
mTorr 0 — 25,000
10,000 — 25,000
1 mTorr
0 — 9,999.9
0.1 mTorr
mmHg 0 — 25.000
10.000 — 25.000
0.001 mmHg
0 — 9.9999
0.0001 mmHg
Microns 0 — 25,000
10,000 — 25,000
1 Micron
0 — 9,999.9
0.1 Micron

“Analog” Vacuum Level Bar Graph
The Vacuum Level Bar Graph has two modes:
Evacuation Progress Indicator
When the pressure is above 25,000 microns (when the display shows ), the
bar graph indicates evacuation progress. The bars progressively drop as the
pressure drops between ATM and 25,000 microns.
Vacuum Level Indicator
Below 25,000 microns, the bar graph allows for a quick visual determination of the
vacuum level achieved. Each bar corresponds to a vacuum pressure range depend-
ing on units according to the following table:
NOTE: The pressure bars indicate Microns when inHg units are selected.
Alternate Numeric Display
The eVac Pro has an Alternate Numeric Display that can indicate Vacuum Leak Rate,
Ambient Temperature, Saturation Temperature, or Programming Time/Progress.
Please refer to the “Programming” section below for programming instructions.
During normal operation, the Alternate Numeric Display may show Vacuum Leak
Rate, Ambient Temperature, or Saturation. Select the display mode by pressing the
key to cycle between LEAK RATE, TEMP and SAT. TEMP.
Vacuum Leak Rate Indicator
The Vacuum Leak Rate Indicator displays the rate of change of vacuum per second
or per minute in the selected units when the LEAK RATE indicator is illuminated. The
reading is positive for increasing pressure and negative for decreasing pressure. The
LEAK RATE Indicator is useful for determining the size of a vacuum leak, if one
exists, or the presence of moisture or outgassing. Under high-pressure conditions
( ), the leak rate indicator shows .
Press and hold the key while the LEAK RATE indicator is showing to switch
between per second and per minute, as indicated by and on the display.
8
Units
Bar
Value
Microns
Pa
Millibar
Millitorr
mmHg
PSI
10K
10,000 — 25,000
1,000 — 3,333.1
10 — 33.331
10,000 — 25,000
10 — 25
0.2 — 0.48342
5K
5,000 — 10,000
500 — 1,000
5 — 10
5,000 — 10,000
5 — 10
0.1 — 0.2
2K
2,000 — 5,000
200 — 500
2 — 5
2,000 — 5,000
2 — 5
0.04 – 0.1
1K
1,000 — 2,000
100 — 200
1 — 2
1,000 — 2,000
1 — 2
0.02 — 0.04
500
500 — 1,000
50 — 100
0.5 — 1
500 — 1,000
0.5 — 1
0.01 — 0.02
200
200 — 500
20 — 50
0.2 — 0.5
200 — 500
0.2 — 0.5
0.004 — 0.01
100
100 — 200
10 — 20
0.1 — 0.2
100 — 200
0.1 — 0.2
0.002 — 0.004
50
50 — 100
5 — 10
0.05 — 0.1
50 — 100
0.05 — 0.1
0.001 — 0.002
20
20 — 50
2 — 5
0.02 — 0.05
20 — 50
0.02 — 0.05
0.0004 — 0.001
10
10 — 20
1 — 2
0.01 — 0.02
10 — 20
0.01 — 0.02
0.0002 — 0.0004

Ambient Temperature Indicator
Internally, the eVac Pro uses a very high accuracy temperature sensor to maintain
proper calibration throughout the entire operating temperature range. This tempera-
ture is shown on the Alternate Numeric Display when the TEMP indicator is illuminat-
ed. The accuracy of the temperature sensor is 0.2˚F or 0.1˚C.
Saturation Temperature Indicator
The saturation temperature of water (i.e. the temperature at which water boils at the
measured pressure) is computed and displayed on the Alternate Numeric Display
when the SAT. TEMP indicator is illuminated. Under high-pressure conditions
( ), is shown on the Alternate Numeric Display.
Press and hold the key while the TEMP or SAT. TEMP indicator is showing to
switch between Celsius and Fahrenheit, as indicated by ˚C and ˚Fon the display.
Protective Boot Accessory
The protective boot accessory provides additional protection for the eVac Pro. The
eVac Pro may be operated with or without the boot installed. For moisture protection,
the boot is provided with a sealed cap where the swivel hook would normally be
attached. To attach the hook with the boot in place, carefully cut the cap from the
boot with a sharp blade.
Swivel Hook
The eVac Pro’s removable stainless steel swivel hook enables hanging of the gauge
and will allow it to swivel freely in any direction. The gauge may be operated with or
without the hook attached. When fastening the hook to the gauge, turn it finger tight
only. Use of a tool to tighten the hook may result in damage to the eVac Pro case.
9

Programming
As a special feature, the eVac Pro includes two related programs: the Evacuation
Program and the Rise Time Testing (RTT) Program.
The Evacuation Program allows for unattended evacuation of large systems, and will
sound an audible/visual alarm when the evacuation procedure is complete, based
upon both an Evacuation Target Pressure and Evacuation Target Time. For example,
a procedure may call for evacuating a system to at least 500 microns, and maintain-
ing that pressure (or less) for at least 15 minutes.
Following a successful evacuation, the RTT Program can consistently ensure proper
evacuation by analyzing the rate-of-rise of pressure vs. time, and automatically signal
a or indication based upon an RTT Target Pressure and RTT Target Time.
Advantageously, a clean, dry, and tight system can successfully a Rise Time
Test in as little as 15 seconds, eliminating the need to wait for the RTT Target Time to
elapse. For example, a procedure may call for ensuring that a system evacuated to
500 microns or less will not exceed 1000 microns after the vacuum pump has been
blanked off over 10 minutes.
Each program consists of both a target pressure (vacuum level) and a time period.
There are 16 possible target pressures, depending upon the units displayed, as
shown in the following table:
The time periods may be programmed between 0 seconds and 100 minutes. To program
the eVac Pro, the Set Mode must be activated:
Programming (Set Mode)
1. Turn the power on by pressing .
2. Select the desired units by repeatedly pressing .
3. Activate the Program Set Mode by pressing and holding SET. The SET and TIME
indicators will show on the display, as well as the currently programmed Evacuation
Target Pressure and Time.
4. While the pressure display is flashing, press and/or hold the or keys to increase
or decrease the Evacuation Target Pressure. When compete, press and release the
SET key.
5. While the minutes display is flashing, press and/or hold the or keys to increase
or decrease the Evacuation Target Time minutes. When compete, press and release
the SET key.
6. While the seconds display is flashing, press and/or hold the or keys to increase
or decrease the Evacuation Target Time seconds. When compete, press and release
the SET key.
10
Units
Microns
Pascal
Millibar
Millitorr
mmHg
PSI
inHg
50
5.0
0.050
50
0.050
0.0010
-29.919
75
10.0
0.100
75
0.075
0.0015
-29.918
100
15.0
0.150
100
0.100
0.0020
-29.917
150
20.0
0.200
150
0.150
0.0030
-29.915
200
30.0
0.300
200
0.200
0.0050
-29.913
300
50.0
0.500
300
0.300
0.0075
-29.910
500
75.0
0.750
500
0.500
0.0100
-29.900
750
100.0
1.000
750
0.750
0.0150
-29.890
1000
150.0
1.500
1000
1.000
0.0200
-29.880
1500
200.0
2.000
1500
1.500
0.0300
-29.060
2000
300.0
3.000
2000
2.000
0.0500
-29.850
3000
500.0
5.000
3000
3.000
0.0750
-29.800
5000
750.0
7.500
5000
5.000
0.1000
-29.700
7500
1000.0
10.000
7500
7.500
0.1500
-29.600
10000
1500.0
15.000
10000
10.000
0.2000
-29.500
15000
2000.0
20.000
15000
15.000
0.3000
-29.300

7. The display will now show the currently programmed RTT Target Pressure and
Time, and the RISE TIME indicator will illuminate.
8. While the pressure display is flashing, press and/or hold the or keys to
increase or decrease the RTT Target Pressure. When compete, press and
release the SET key.
9. While the minutes display is flashing, press and/or hold the or keys to
increase or decrease the RTT Target Time minutes. When compete, press and
release the SET key.
10. While the seconds display is flashing, press and/or hold the or keys to
increase or decrease the RTT Target Time seconds. When compete, press and
release the SET key.
11. The gauge will beep three times (if sound is enabled), and return to normal
mode. The new program is now saved.
12. At any point in the Program Set Mode, pressing and holding the SET key will
result in saving the current program and returning to normal mode.
13. Once programmed, the eVac Pro will remember the settings until changed
again, even if the power is turned off or the battery removed.
NOTE: The units cannot be changed while in the Set Mode.
Executing a Program (Run Mode)
Press and release . The RUN indicator will illuminate and (EVAC) or
(RISE), indicating the current program execution mode, will flash on the main
display. Press the key to select the desired execution mode. The main display will
toggle between and with each press of the key.
Executing the Evacution Program
1. Ensure is flashing on the display. Use the to select , as above,
if not.
2. Press to start the program.
3. The RUN and TIME indicators will illuminate on the display. RUN will flash to
indicate the program is running.
4. Start the vacuum pump.
5. When the vacuum pressure drops to less than the target evacuation pressure, the
timer will start. Subsequently, if the pressure exceeds the target evacuation
pressure, the timer will stop and resume counting when the pressure again drops
to less than the target pressure.
6. When the timer expires, the eVac Pro will sound an alarm, flash the backlight, and
blink the DONE indicator. Press any key to silence the alarm. The program
is complete.
7. Blank-off and stop the vacuum pump.
Executing the Rise Time Test Program
1. Ensure the vacuum pump is blanked-off and stopped.
2. Ensure is flashing on the display. Use the to select , as above, if not.
3. Press to start the program.
4. The RUN and RISE TIME indicators will illuminate on the display. RUN will flash
to indicate the program is running.
5. Immediately, the eVac Pro will begin monitoring the rise rate of pressure, though
the clock will remain stopped until the pressure exceeds the Evacuation Target
Pressure.
6. If a determination is made that the pressure will not exceed the Rise Time
Pressure Target within the allotted time, the eVac will alarm and indicate
regardless of the time remaining. The analysis is performed, and a can be
achieved, even if the clock is not running (i.e. system is still below the Evacuation
Target Pressure). 11

7. If the pressure exceeds the RTT Target Pressure before the RTT Target Time is
achieved, the eVac Pro will alarm and show
to indicate that the test has failed.
8. In either case, pressing any key will silence the alarm. In the case of a , the
clock will continue counting for further manual analysis. This can be stopped by
pressing the key. In the case of a , normal operation will immediately resume.
While in the Run Mode, the gauge may sleep after 5 minutes of high pressure. The
gauge will wake and continue the program normally once the pressure drops below
25,000 Microns. The gauge may be manually wakened from sleep by pressing any
key. In the Run Mode, the Auto Power-Off feature is disabled.
Stopping a Program
At any time during the Run Mode, the program can be canceled by pressing and
holding .
NOTE: The units cannot be changed while in the Run Mode. Pressing the Mode key
during the run mode will toggle between leak rate and time.
Maintenance
The eVac Pro should provide many years of service with no maintenance required.
When not in use, the dust cap should remain in place over the sensor port. Clean the
plastic enclosure with a damp (not wet) rag. Mild detergent is acceptable, but use no
solvents. Take care not to expose the vacuum sensor to oil. If the Oil Sensor
(described above) indicates a contaminated sensor, follow the Sensor Cleaning
Procedure below.
Cleaning the Vacuum Sensor
If the vacuum sensor becomes contaminated with oil (as indicated by the Oil Sensor),
carefully follow this procedure:
1. Power off the eVac Pro.
2. Shake the gauge to remove any large quantities of oil from the sensor.
3. Using an eyedropper or syringe, carefully apply a few drops of rubbing alcohol
inside the sensor vacuum port. DO NOT INSERT ANY OBJECT INTO THE
PORT, AS THIS WILL PERMANENTLY DAMAGE THE SENSOR.
4. Place your finger over the port and shake for a few seconds.
5. Remove your finger and shake out the alcohol.
6. Repeat steps (3) – (5) at least three times.
7. Allow the sensor to air dry over at least an hour, or pull a vacuum on the sensor to
dry it more quickly (a few seconds).
8. Replace the battery and turn on the gauge. The message and OIL
indicator should be off. If it is still on, repeat the cleaning procedure.
9. If, after repeated cleaning, the message or the OIL indicator is still
illuminated, or, if full accuracy is desired, perform a calibration cycle as detailed in
the Calibration section below.
NOTE: It is important to remove all alcohol vapors from the sensor, either through
air-drying or via vacuum. Any remaining vapors will cause an incorrect vacuum
reading.
12

Calibration Test
The eVac Pro should rarely require recalibration, though it may be necessary to know
that your gauge is calibrated properly for full accuracy. The Calibration Test mode
assures you that the eVac Pro is calibrated to factory specifications. Test the calibra-
tion as follows:
1. Power off the eVac Pro.
2. Important: Expose the eVac Pro to atmospheric pressure.
3. Press and hold (do not release) the key for about 5 seconds.
4. The display will show if the instrument is calibrated properly.
5. The display will show if the instrument requires calibration. Please see
the Calibration section below.
Calibration
If the Calibration Test indicates recalibration is required, the gauge may be recalibrat-
ed. Unlike any other vacuum gauge, the eVac Pro can be easily recalibrated to
factory specifications without any special equipment, with the following procedure:
1. For best results, clean the sensor with alcohol prior to calibration. Ensure the
sensor is completely dry before proceeding.
2. Power off the eVac Pro. If necessary, install a fully charged battery into the gauge.
3. Place the dust cap over the vacuum fitting.
4. Hold while pressing . As soon as the power turns on, release and
then press it quickly at least three times. The indicator should illuminate, and
should show on the Main Numeric Display. If not, turn the power off again
and repeat.
5. Place the eVac Pro in a clear Ziploc (resealable zipper storage) bag, press out
any extra air, and seal.
6.
Place the bagged eVac Pro into a freezer with a temperature of less than –5˚C (23˚F).
7. Allow the eVac Pro to cool to below -2 ˚ C (28.4 ˚ F). At this point, the alarm will
sound and the display will change to .
8. Remove from freezer and press any key to silence the alarm.
9. Place the eVac Pro undisturbed in an area with a room temperature of at least
23
˚ C (73.4 ˚ F) but no greater than 30 ˚ C (86 ˚ F).
10. Allow the eVac Pro to warm to 20
˚ C (68 ˚ F). At this point, the alarm will sound,
and will show on the display.
11. Press any key to silence the alarm. The eVac Pro is now calibrated to factory
specifications.
Note: For accurate calibration, allow the eVac Pro to warm slowly. Attempting to
accelerate the warming by using a heat source will not provide satisfactory results.
During the cooling/warming process, the temperature will be indicated on the
Alternate Numeric Display in degrees Celsius. The calibration process may be
canceled at any time by turning off the eVac Pro or by pressing and holding .
The previous calibration will be unchanged.
13

Low Temperature Operation
The eVac Pro can operate accurately at temperatures as low as 10˚F (-12˚C). While
operating below freezing (32˚F/0˚C), the display update rate will slow from 3.5
readings every second to one reading every two seconds.
For satisfactory battery life at low temperatures, a 9V Lithium battery is recommended.
Troubleshooting
Under certain conditions, the display may read or . Please use the
table below to determine and fix the problem:
14
Display
Mode
Possible Problem
Solution
Normal
Operation or
Run Mode
Sensor Contaminated
Clean the Vacuum Sensor
Ambient Temperature too
Low
Turn the eVac Pro off,
warm the vacuum port with
your hand, turn the eVac
Pro back on.
Calibration Sensor Contaminated
Clean the Vacuum Sensor
and Restart Calibration
Normal
Operation or
Run Mode
Sensor Failure Contact Customer Service
Calibration
Gauged Warmed too
Quickly
Restart Calibration. Allow the
Gauge to Warm Slowly
Gauge Disturbed During
Calibration
Restart Calibration. Leave
the Gauge Undisturbed
During Warming Phase.

Frequently Asked Questions
Q. How often must I calibrate the eVac Pro? Calibration of the eVac Pro is only necessary
when the Calibration Test indicates that calibration is required. Regardless, frequent cleaning
and/or calibration will not adversely affect the long-term reliability of the instrument. For best
results, ensure the sensor is clean and dry, and the dust cap is in place, prior to calibration.
Q. Can I use the eVac Pro to check the proper operation of my vacuum pump? Yes. Attach
the eVac Pro directly to the pump with a short hose or coupler. Turn the pump on, open the
blank-off valve, and close the ballast. A good pump with clean and dry oil will typically pull very
quickly to less than 100 microns (generally around 25 microns for a two-stage pump). Always
close the blank-off valve and/or disconnect the BluVac Pro prior to turning off the pump so as to
avoid oil contamination of the sensor.
Q. The eVac Pro does not indicate acceptably low pressure when I test my pump. Ensure
the pump oil is clean and dry (it should be completely clear when viewed through the pump’s
sight glass). Replace the oil. Ensure the pump ballast is completely closed and the blank-off
valve is completely open, and all fittings are tight and seals are not damaged. If low pressure is
still not achieved, the pump may be damaged or worn.
Q. I’ve attached the eVac Pro directly to my pump with a short hose or coupler. As soon
as I blank off the pump, the indicated pressure rises rapidly. Is the eVac Pro’s sensor
leaking? No. There will always be molecular-sized leaks, outgassing, and/or permeation in any
hose or fitting, and the pump’s blank-off valve may not be entirely gas tight. The indicated
pressure will rise due to the small internal volume of the hose or coupler.
Q. What is the recommended method for attaching the eVac Pro for evacuation service?
Ideally, the eVac Pro should be as close to the internals of the system under evacuation, and
as far from the vacuum pump as possible. Attaching the eVac Pro to the auxiliary port of a core
removal tool (CRT) connected directly to a service port is the best method. The ball-valve of
the CRT can be closed to completely isolate the system from the pump and hoses, thereby
allowing for an accurate rise-time test at the completion of evacuation. Additionally, removing
the Schrader core(s) via the CRT and using large diameter hoses will greatly speed the
evacuation process.
Q. I accidentally exposed the eVac Pro to high-pressure refrigerant. Did I damage the
eVac Pro? No. The eVac Pro’s sensor is rated to 500 PSI overpressure, and can be directly
exposed to gas/liquid refrigerant. At worst, the sensor may be exposed to oil, in which case the
oil indicator will activate and cleaning/calibration may be required.
Q. I removed the eVac Pro from the system under vacuum, but the indicated pressure
rises slowly and/or the gauge does not return to Hi-P. Is the eVac Pro damaged? No. The
slow rise in pressure is due to residual refrigerant gas captured in the sensor. Gently blowing air
into the sensor to remove the residual gas will effect an immediate rise to Hi-P.
Q. How do I use the leak rate indicator? The leak-rate indicator is especially useful for system
diagnostics during a rise-time test. If the indicated leak rate is stable and constant, this usually
indicates a physical vacuum leak. If the leak rate is stable, but decreases as the pressure rises,
this usually indicates evaporating moisture or outgassing. If the leak rate is unstable (bouncing
between different numbers), this usually indicates liquid water boiling off inside the system.
Since the resolution of the eVac Pro is so high, it may be difficult to achieve a zero leak-rate.
This is not a problem as long as the system meets the manufacturer’s recommended vacuum
rise-time performance.
15

Frequently Asked Questions
Q. Why does the ambient temperature indicator show a different temperature than my
room thermometer? The ambient temperature indicator actually measures the temperature of
the metal sensor housing and the gas contained within the sensor. This temperature may be a
few degrees different than room temperature. The temperature sensor itself is inherently
accurate within 0.2˚F (0.1˚C) and requires no calibration.
Q. My eVac Pro reads a different pressure than my other vacuum gauge from another
manufacture. Which gauge is correct? Unlike all other micron gauges, the eVac Pro’s
accuracy is independent of temperature and pressure. Therefore, you can be confident that the
eVac Pro’s reading is correct. Other gauges are calibrated at a specific temperature and
pressure (i.e. 500 microns and 77˚F (25˚C)). The accuracy of those gauges is necessarily
underated when operated at pressures and temperatures different than the calibration values.
Q. I’ve started a Rise Time Test Program, but the clock doesn’t run. Why? For consistency
of rise time testing, the Rise Time Clock does not begin counting until the pressure has risen
above the Evacuation Target Pressure. On a very clean, dry, and tight volume, this may not
happen before a result is achieved. Regardless, a result ensures that the pressure
would not have risen between the Evacuation Target Pressure and the Rise Time Target
Pressure within the allowed Rise Time Target Time Period.
Q. I am still having problems using the eVac Pro and/or understanding the readings it is
giving me. What should I do? Please, contact us! Use our website at www.yellowjacket.com or
call us at [phone] between 8:00AM and 5:00PM CST. We will be happy to help.
4