Mastercool IntellaSense III Combustible Gas Leak Detector

Introduction

You have purchased an intelligent combustible gas leak detector, model 55975. This device features a new low-power metal oxide gas sensor with superior performance, including lower current consumption and extended sensor longevity. The sensor offers high sensitivity and fast response for detecting extremely small levels of chlorofluorocarbon gases.

A powerful microprocessor automatically optimizes the sensor's operating conditions for peak performance throughout the product's life. Upon activation, the unit briefly displays the last used settings via one or more of its six LEDs. The sensor then enters a warm-up sequence, lasting a minute or less, indicated by six green vertical LEDs that extinguish sequentially until only one green (READY) LED remains lit, signaling readiness.

The LED indicators show the selected sensitivity range: Green for the least sensitive level, Yellow for medium sensitivity, and Red for the most sensitive level. The default sensitivity upon initial turn-on is GREEN.

WARNING: This symbol alerts users to important operating, maintenance, or servicing instructions found within this document.

Specifications

The "Super Sensitive Function" allows the unit to achieve higher sensitivity than standard settings for locating very small leaks.

Probe Properties

• Intelligent tip with environment sensing to help eliminate false alarms.
• Flexible 15.5-inch (approx. 39.3 cm) probe length for reaching difficult areas.

Display Properties

Status Indicators: Three (3) vertical LED indicators display the unit's condition and state immediately after power-on. This display lasts for approximately 3 seconds.

• LED #6: Identifies a LOW BATTERY condition.
• LED #5: Identifies the HIGH RANGE (HR) setting is enabled.
• LED #4: Identifies the LOW RANGE (LR) setting is enabled.

Warm-Up Status: Initially, all six (6) vertical LED indicators are ON. They then extinguish sequentially until only one GREEN LED (READY) remains lit, signaling readiness. This warm-up sequence takes less than 1 minute.

LED Indicator Diagram Description: The device features six vertical LEDs. LED 1 is labeled READY, LED 2 is CA, LED 3 is INT/WT, LED 4 is LR, LED 5 is HR, and LED 6 is the battery symbol. These LEDs indicate the operational status, sensitivity range, and battery level.

Definition of Display Legends

• BATTERY SYMBOL (LED #6): Illuminated when the battery is near the end of its life.
• HR (High Range): Select for detecting hard-to-detect gases.
• LR (Low Range): Select for detecting easy-to-detect gases.
• INT/WT: Triggered by conditions like excessive air turbulence, accidental probe touch, or blowing on the probe, activating the interference detector.
• CA (Contaminated Atmosphere): Turns ON when contamination is detected for a period.
• READY: Indicates the unit is ready for use.

Keypad Functions

Keypad Description: The keypad includes buttons for ON/OFF, PEAK/HR/LR, VOLUME/MUTE, and HML.

• ON/OFF: Turns the unit ON and OFF with a push-on, push-off sequence.
• PEAK/HR/LR: This key has a dual purpose:
  • Assists in locating the "largest leak" in a system with multiple leaks.
  • Enables switching between HR (high range) and LR (low range) modes.
• VOLUME/MUTE: Sequentially selects the audible "beep" level: normal, low, or mute. All alarms are heard at maximum level, even when muted.
• HML (HIGH/MEDIUM/LOW SENSITIVITY): Selects the sensitivity range. The LED color and beep tone change with each selection (High=Red, Medium=Orange, Low=Green).

Operation

Battery Preservation Feature

An automatic timer shuts off the unit after 3 minutes of inactivity. The timer resets if the unit alarms or if any key is pressed.

Displaying Status Settings

Upon initial turn-on, pressing the ON/OFF key momentarily displays the unit's status for approximately 3 seconds. The following information is shown by the LEDs:

• LED #6 ON: Battery is nearing end-of-life and should be replaced.
• LED #5 ON: Unit is in High Range (HR) setting for detecting difficult gases.
• LED #4 ON: Unit is in Low Range (LR) setting for detecting easy gases.

Displaying Warm-Up Status

All six (6) LEDs turn ON and sequentially extinguish until only the GREEN READY LED remains. The audible "beep" begins (unless muted), indicating the unit is ready. This process takes less than 1 minute. The unit defaults to LOW sensitivity (indicated by the GREEN LED) upon initial turn-on.

Changing Audible Level

Use the Volume/Mute key to sequentially change the audible "beep" level (Normal, Low, Mute). The unit visually confirms the selection:

• Normal: Six LEDs flash briefly; beep resumes at maximum level.
• Low: Three LEDs flash briefly; beep resumes at a lower level.
• Mute: Only the READY LED stays ON; audible is muted.

The selected audible level is stored until changed.

Changing Sensitivity

Press the HML key to cycle through sensitivity levels:

• High Sensitivity: LED #1 (READY) turns RED.
• Medium Sensitivity: LED #1 turns YELLOW.
• Low Sensitivity: LED #1 turns GREEN.

During leak detection, all LEDs will match the color of the READY light.

Changing Operating Range (HR to LR)

After warm-up and when the READY indicator is ON, press and hold the PEAK/HR/LR key until all LEDs turn OFF. Release the key. The unit will perform a new warm-up sequence with the selected range.

Reducing False Leak Detection

Under Adverse Conditions: To distinguish true leaks from false alarms caused by air turbulence or accidental probe contact, the interference detector momentarily interrupts operation. The audible beep stops, and the INT/WT LED (#3) and READY LED (#1) flash briefly. When ready to resume, LED #3 extinguishes, LED #1 turns ON, and the beep resumes.

In a Contaminated Environment: If a contaminated area is detected for a period during a leak search, the sensor responds by turning OFF the READY LED (#1), stopping the beep (unless muted), and turning ON the INT/WT LED (#3). The unit then re-calibrates. After re-calibration, the CA LED (#2) and READY LED (#1) turn ON, and the beep resumes, indicating readiness in the contaminated environment.

Quick Start Tips for Finding Leaks

Sudden probe movements or blowing into the sensor can cause false alarms. Integrated electronic sensors detect and minimize these events. If interference is detected, LED #3 flashes, and normal operation resumes once the READY LED appears.

1. Initial Search: If the leak magnitude is unknown, start with LOW sensitivity to locate medium to large leaks.
2. Probing Technique: Slowly move the probe approximately 3/8 inch (9 mm) above the suspected leak area. Move the probe past the leak to clear it if detected. Do not hold the probe directly at the leak site. For verification, return the probe to the area where a leak was detected.
3. Increasing Sensitivity: If no leaks are found with LOW sensitivity, increase to MEDIUM and repeat step 2.
4. Small Leaks: For extremely small leaks (0.1 oz/yr or less), use HIGH sensitivity. Position the probe tip as close as possible to the surface without physical contact. Touching an object will trigger a brief interruption (INT). In contaminated environments, the sensor will automatically adjust.

Maintenance

Installing or Replacing Batteries

Remove the battery cover (as shown in Figure 1) and take out the old batteries. It may help to turn the unit vertically and shake them out. Install two C-size alkaline batteries, observing correct polarity (as shown in Figure 1). Replace the battery cover and secure it with the screw.

Figure 1 Description: An illustration shows the battery compartment cover, a screw for securing it, and the correct placement of two C-size batteries with their positive (+) and negative (-) terminals indicated.

Replacing the Sensor

To replace the sensor:

1. Firmly grasp the flexible probe near the end with one hand.
2. With the other hand, unscrew the nozzle portion from the threaded probe tip counter-clockwise.
3. Remove the metal washer, rubber washer, and then the sensor in that order. Note the orientation of the key on the sensor being removed.
4. It is advisable to replace the filter inside the nozzle simultaneously. A long, thin object (like an o-ring pick) may be needed to remove the microfiltration membrane from the nozzle.

Figure 2 Description: An exploded view diagram shows the probe tip assembly. Components include the probe, nozzle, filter, sensor, rubber washer, and metal washer. The diagram highlights the sensor's key and the probe's key slot.

When installing a new sensor:

• Align the sensor's tab key with the key slot on the probe.
• Ensure the sensor's 3 pins are correctly inserted into the probe end's corresponding pins.
• Verify the sensor is properly seated.
• Install the rubber washer (as shown in Figure 2), followed by the metal washer.
• Insert the new filter and screw on the nozzle while holding the probe end firmly.
• DO NOT USE TOOLS for tightening the tip assembly; hand-tighten only.

Leak Test Vial

A leak test vial is provided to verify the correct operation of the leak detector.

1. Turn the leak detector ON and wait for the warm-up sequence to complete. The READY LED will illuminate, and an audible "beep" will sound (unless muted). Set the sensitivity level to MEDIUM.
2. Remove the vinyl cap from the vial to expose the small leak hole (as shown in Figure 3A). DO NOT UNTWIST THE BLACK CAP FROM THE BOTTLE.
3. Figure 3A/3B Description: Figure 3A shows the small leak hole on the vial's cap. Figure 3B illustrates positioning the probe tip close to this hole.
4. Briefly place the probe tip close to the small hole (as shown in Figure 3B) until an audible alarm is generated. This confirms proper operation. Reseal the vial with the vinyl cap and return it to its case.

PRECAUTION! Holding the test vial too close to the probe tip for an extended period can saturate the sensor, causing the detector to interpret it as a large leak or contaminated atmosphere. This precaution also applies during leak location. If this occurs, the CA LED may illuminate after self-calibration. The unit remains usable if the READY LED is lit. The CA LED will eventually disappear as the unit returns to a non-contaminated environment and self-calibrates.

Replacement Parts

Replacement parts and accessories for the 55975 Leak Detector are available from the dealer where the instrument was purchased.

California Proposition 65 Warning

WARNING: This product can expose you to chemicals, including lead and Di(2-ethylhexyl) phthalate, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.

Warranty and Liability

Mastercool Inc. warrants the 55975 Refrigerant Leak Detector against defects in material and workmanship for one year from the date of purchase. This warranty does not cover items that deteriorate with normal use, such as batteries, sensors, and filters, nor does it cover products showing evidence of misuse, accident, unauthorized repair, or alteration.

Mastercool's liability is limited to the repair or replacement of the defective product or part, provided it is returned to Mastercool (transportation prepaid) no later than 30 days after the warranty expires and is determined to be defective due to material or workmanship.