Tinker & Rasor M/2 - Multi Voltage / Wet Sponge Holiday Detector (9v, 67.5v, 90v DC)

The Model M/2 Holiday Detector is a highly sensitive device designed to locate holidays (pin holes, voids, etc.) in thin film protective coatings of relatively high electrical resistance when such films are applied to the surface of material of low electrical resistance. In these applications, such as painted metal surfaces, the Model M/2 Holiday Detector will locate these points very accurately with an audible and visual signal. This method of inspection of thin film is a non-destructive test and will not injure the protective coating.

Output voltages

The M/2 has multiple voltage outputs that can be selected. These outputs have been determined to meet varying international standards regarding the use of the equipment. The Model M/2 Low Voltage (Wet Sponge) Holiday Detector is designed to meet or exceed the requirement of the following standards (Partial List):

• NACE RP0188, SP0188, TM0384
• ASTM D 5162-A, G6, G62-A
• ISO 8289, 14654, 14655, 14656, 15741, 16967, 29601
• AUSTRALIA AS 3894-2
• JAPAN JIS 6766

The four output settings are:

• 9v @ 90 K-ohms
• 67.5 volts @ 80 K-ohms
• 67.5 volts @ 90 K-ohms
• 90 volts @ 400 K-ohms

Equipment overview

The Model M/2Holiday Detector consists of a portable battery powered electronic instrument, a wand handle, and sponge assembly (open cell sponge ships compressed, will expand with water), and ground wire. The instrument is housed in a sturdy plastic case with provision for attachment of optional (not included) headphones.

The detector is a “non-destructive wet sponge” type holiday detector. The basic electronic design of the Model M/2 Holiday Detector is that of a very sensitive circuit which is energized by one 9v battery. When current of 500 or 700 (+/- 10/%) micro-amperes flows in the circuit, an audible and visual signal is actuated.

The exploring electrode is open-cell sponge material and is conductive when saturated with a wetting solution. The sponge electrode is attached to the non-conductive wand handle by means of the bolt with knob, plastic sponge holder and backing plate.

The wetting solution should consist of potable tap water and a wetting agent. The ratio of one (1) ounce agent to one (1) gallon tap water is recommended.

Testing overview

The protective coatings should be dry and free of all contamination prior to electrical holiday testing. Proper curing and drying time of the protective coating must be established prior to conducting electrical holiday testing.

The dry film thickness should not exceed 20 mils when electrical holiday testing is done with the low voltage Model M/2Holiday Detector. Film thickness should be determined with a non-destructive dry film thickness gauge to make sure limits are not exceeded.

Special Note: Ordinary tap water will generally suffice to dampen the sponge electrode, provided the protective coating thickness does not exceed 10 mils. The factory recommended practice is to use a wetting agent at all times, regardless of coating thickness up to 20 mils. The low voltage holiday detector is not recommended for coatings greater than 20 mils of thickness.

Calibration

Factory calibration on Model M/2 Holiday Detectors is for the voltages and resistances of each of the four (4) output settings. All voltages are calibrated to a tolerance of +/- 5%.