Imperial LD900 User manual
Refrigerant Gas Leak Detector
Detects all HFO, HFC, HCFC, and CFC
Refrigerants including blends
WARRANTY
The LD900 Refrigerant Gas Leak Detector is warranted to be free of
defects in materials and workmanship for a period of two years from the
date of purchase. This warranty applies to all repairable instruments that
have not been tampered with or damaged through improper use including
unauthorized opening of the unit. Tools should be returned to the buyer’s
place of purchase.
SERVICE/TECHNICAL QUESTIONS
CALL TOLL FREE: 888.467.8665
30333 Emerald Valley Pkwy. • Glenwillow, Ohio 44139 • 888.467.8665
REPLACEMENT PARTS
Item Part Number
Sensor with Sensor Tip & Filter S77694
Sensor Filters (5 pack) S77695
Leak Test Vial S77696
Sensor Tip with Filter S77698
Parts Kit (includes sensor, test vial, & lter kit) S77697
Carrying Case S77699
LD900
User Manual
www.imperial-tools.com
Design certied by ASCI
and Intertek to meet SAE
J2791 & ASCI J2913,
EN14624-2012 & ASHRAE
173-2012
Made in U.S.A.
LeakDetectors-LD900-UserManual.indd 1-1 12/7/16 1:08 PM
INTRODUCTION
The LD900 features a long life solid electrolyte sensor technology that is designed
to detect more current and difcult HFC refrigerants such as R-134a, R-410A,
R-404A, R-407A, and R-507 in addition to the new HFO-1234yf and all HCFC (R-
22) and CFC (R-12) refrigerants including SNAP approved hydrocarbon blends.
Our unique digital leak size indicator takes the guesswork out of whether to repair
a small leak. The digital display is independent from the audio alarm and sensitivity
level, allowing the precise pinpointing of the leak source.
The LD900 does not require rechargeable batteries.
FEATURES
• Unique numeric leak size indicator
• Long life, stable sensor
• R-134a sensitivity .05 oz/yr
• R-1234yf sensitivity .015 oz/yr
• R-22 sensitivity .025 oz/yr
• Design certied to meet SAE J2791, SAE J2913, European EN14624
• Automatic calibration and reset to ambient
• Visual LED leak alarm near sensor
• 3 adjustable sensitivity levels
• Low battery indicator
• True mechanical pump
• Audio mute function
• Uses 4 AA alkaline batteries
• CE Certied
• Comfortable Sanoprene grip
• 2-year warranty includes sensor
• Made in USA
OPERATING INSTRUCTIONS
1.TURN ON: Press the ON/OFF button once to turn on and again to turn off.
NOTE: Hold button down for approximately 1 second to turn unit off.
2.WARM UP: The detector automatically starts heating the sensor. During the
heating cycle, the digital leak size indicator will ash 0 and the detector will sound
a slow “beep”. Warm up time is usually less than 20 seconds.
3.READY: The detector is ready to begin searching for leaks when the ashing
0 stops and the green sensitivity LED turns on. The audio “beep” increases in
frequency and the probe LED begins to blink steadily.
4.SEARCHING: When searching for leaks, move the sensor tip along A/C lines
and ttings no further away than 0.4 in. (9.5 mm) and no faster than 3 in./sec. (75
mm/sec.) If the detector alarms, make smaller sweeps back and forth until the leak
source can be pin pointed. NOTE: The LD900 only responds to changes in leak
concentration. The alarm will re-set automatically if the sensor tip is held at the leak
source. If the leak detector has been out of use for an extended period, weeks or
months, the following action is recommended. Power on the instrument and allow it
to come out of warm up. Then run it with the sensitivity level in the Hi (high) position
for several minutes before testing it with the Leak Test Vial. This action will guarantee
that the sensor is fully conditioned for maximum response to refrigerant gas.
Digital Leak Size Indicator
Low Battery Indicator
Sensitivity Level Indicators
Audio Mute & Sensitivity Level Selectors
Power On/Off
LD900 CONTROL PANEL
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LEAK SIZE INDICATOR
The digital leak size indicator remains off normally but once a leak is detected, a
number from 1-9 will be displayed for all HFC and HCFC refrigerants regardless of
the sensitivity setting.
The number will continue to increase or decrease depending on the amount of
refrigerant sensed. The maximum value will be displayed once the leak source has
been located. The table below can be used to approximate the size of leak:
Maximum # Approx. Leak Size Approx. Leak Size
Displayed (oz/yr) (g/yr)
1 -3 < 0.1 <3
4-6 0.1 to 0.5 3 to 14
7-9 >0.5 >14
LOW BATTERY INDICATOR
Replace the 4 AA Alkaline batteries when the red LED on the control panel is lit.
Follow battery installation instructions under Maintenance section.
AUDIO MUTE FUNCTION
To silence or mute the audio beep and alarm signal, press the MUTE button.
To restore the audio sound, press the MUTE button again. (Note: a few seconds
is required to restore sound if the mute button is pressed in rapid succession.)
ADJUSTING SENSITIVITY LEVELS
The leak detector will default to the NORM sensitivity level automatically once the
unit comes out of the warm up cycle and the green LED will turn on.
To change sensitivity levels, press the SENS once for HI sensitivity (red LED will
turn on) and again for LO sensitivity (yellow LED will turn on).
LEAK TEST VIAL
The leak detector comes with a Leak Test Vial that allows the user to make sure
the detector is performing properly. To test:
1.Remove the colored label dot in the center of the screw cap to expose the
vent hole in the top of the screw cap. (see g. below).
2.Turn on the leak detector and allow the instrument to complete the warm
up cycle.
3. Place the sensor close to the small hole in the top of the Leak Test Vial.
The beep rate should increase and the Digital Leak Size Indicator should display a
number from 3-6 indicating that the sensor and the electronics are working properly.
NOTE:
Replace the Test Vial back in the nylon bag when not in use to extend the
shelf life. Replace Test Vial when the green color is less than ¼ full or at the time of
the expiration date.
Remove label dot over
vent hole before testing
Vial cap with vent hole
Expiration date on label
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BATTERY MAINTENANCE
Install Batteries: Remove screw located at rear end of unit and pull down
hinged battery door to open as shown. Always insert all four batteries into the
battery compartment in the same direction. Note: polarity mark on the inside of the
battery door for proper battery orientation.
PRODUCT SPECIFICATIONS
Model # LD900
Name Leak Detector, Refrigerant Gas
Sensitivity .05 oz/yr R134a, .015 oz/yr R1234yf, .025 oz/yr R22
Sensor Life > 10 years
Response Time Instantaneous
Power Supply 4 AA Alkaline batteries
Battery Life 4-6 hours continuous
Warm up time < 20 seconds
Probe length 17 inches (43.8cm)
Numerical Display 7 segment digital display (1 to 9)
Weight, lbs. 1.5 lbs. (0.68kg)
Warranty 2 years (includes sensor)
EN14624-2012 TEST SPECIFICATIONS
Minimum/Maximum Sensitivity Threshold (xed) 1 gm/yr minimum, >50 gm/yr maximum
Minimum/Maximum Sensitivity Threshold (moving) 3 gm/yr minimum, > 50 gm/yr maximum
Minimum Detection Time (1gm/yr) Approx. 1 sec
Clearing Time Approx. 9 seconds after exposure to >50 gm/yr
Minimum Threshold after Maximum Exposure 1 gm/yr
Sensitivity Threshold in Polluted Atmosphere 1 gm/yr
Calibration Frequency 1/yr check with calibrated leak Standard
CROSS SENSITIVITY TO AUTOMOTIVE CHEMICALS
Some automotive solvents and chemicals have similar hydrocarbon properties as R134a and may elicit a positive
response. Before leak checking, clean up any chemicals in the list below that elicit a positive response
Chemical Name/Brand Response
Rain-X Windshield Wash Fluid Y
Ford Spot Remover (Wet) Y
Ford Rust Inhibitor Y
Ford Gasket Adhesive (Wet) Y
Loctite Natural Blue degreaser (diluted) Y
Ford Brake Parts Cleaner Y
Ford Silicone Rubber (uncured) Y
Motorcraft Antifreeze heated to 160° F Y (partial)
Gunk liquid wrench Y
Ford silicone lubricant N
Ford Pumice lotion (with solvent) Y
Ford Motorcraft brake uid Y
Ford Carburetor Cleaner Y
Dextron Transmission uid heated to 160° F N
Quaker State Motor Oil heated to 160° F N
SENSOR MAINTENANCE
Replace Filter: Unscrew sensor tip as shown to replace lter. Replace lter
whenever it becomes visibly dirty or every 2 to 3 months depending on use.
Replace Sensor: Remove sensor by pulling out of socket. Install the new sensor
by aligning the Keyway notch in sensor cover with the raised keyway on sensor
socket holder (see gure below).
Note: Do not force sensor into socket. Misalignment can damage the sensor pins.
IMPORTANT:
The instrument’s software is designed to alert the user if the sensor is dislodged or
defective. If the sensor is not fully inserted into the six-pin socket, or if it is defective, the instrument will not come
out of the “Warm Up” mode for proper operation when the power button is turned on. Additionally, if the instrument
becomes unstable during its operation, it is an indication that the sensor may be defective or dislodged.
Unscrew tip to
replace lter
Filter Push straight on (do not
twist) to install sensor
Pull straight out (do not
twist) to remove sensor
Keyway alignment
Polarity mark
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