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10

Gmic Acoustic Leak Sounding System

Introduction

The Gmic (pronounced Gee Mike) is a highly effective ground microphone.  It
consists of a lightweight portable amplifier module, a set of mono headphones, and a
combination listening probe and ground microphone.

It is an effective electronic instrument for locating and pinpointing leaks from buried
water pipes.

Both visual and audible indications of signal strength (and consequent proximity) are
provided to enable operators to quickly and accurately confirm leak positions.

The control module is battery powered and provides up to 50 hours operational use
before a recharge is required.

Although the system is rugged and shower-proof (to IP65), it contains electronic
circuitry and should handled with care.  The equipment should be kept dry and clean.
Where necessary it should be cleaned with a damp cloth; abrasive materials must
not be used.

Note

:  The headphones supplied with the Rmic cannot be interchanged.  The

impedance of the headphones is matched to the Rmic control unit during
manufacture.

Key features

• 

Lightweight, easily portable system

• 

Excellent acoustic performance

• 

Easy to use control unit

• 

Membrane keypad

• 

Backlit multifunction LCD

• 

25 preset filter combinations

• 

Versatile – ground microphone and hand probe configurations

• 

Military specification connectors

• 

Robust construction for field use

• 

Rechargeable batteries (up to 50 hours use)

• 

Compact case containing full system

Summary of Contents for Lmic

Page 1: ...and Rmic Operating Manual Palmer Environmental Ty Coch House Llantarnam Park Way Cwmbran NP44 3AW United Kingdom Tel 44 0 1633 489479 Fax 44 0 1633 877857 Email info palmer co uk Web www palmer co uk...

Page 2: ...Preparing the Lmic for use 7 Using the Lmic 8 Lmic Technical specification 9 Gmic Acoustic Leak Sounding System 10 Gmic Controls 12 Preparing the Gmic for use 13 Using the Gmic 14 Gmic Technical Speci...

Page 3: ...and even household situations and can be used as a tool as part of a plumbing tool kit Gmic is a more sophisticated piece of equipment containing filters and the option of aviation headphones This com...

Page 4: ...ipeline both through the water and the pipe wall as well as into the ground around the pipe The noise travels much better through hard materials so that the noise travels much further along metallic p...

Page 5: ...regular positions on the ground until you have identified the area of maximum noise level Note When you are listening on pipe fittings the location of the point of maximum noise will probably not indi...

Page 6: ...ries Any misuse of these batteries may result in explosion or fire They must not be used in any other application or used with any other equipment Only batteries supplied by Palmer Environmental must...

Page 7: ...leaks audibly from ground level sound pipe fittings penetrate soft ground to listen for leaks or carry out traditional acoustic surveys Equipment list 1 Lmic hand held control unit 2 Microphone unit w...

Page 8: ...arger power lead to the 240V AC supply The Lmic can then be charged overnight An optional accessory is the car cigarette lighter adapter that can also be used to charge the batteries Battery replaceme...

Page 9: ...r and connect the microphone cable to the forward connector Put on the headphones and press the trigger button underneath the hand held unit to listen for leaks The volume sensitivity can be adjusted...

Page 10: ...accessory Charge time Overnight charge Microphone housing High sensitivity piezo electric sensor mounted in rubber housing with integral strain relief Low noise 0 75m cable detachable Weight 400g Foo...

Page 11: ...a recharge is required Although the system is rugged and shower proof to IP65 it contains electronic circuitry and should handled with care The equipment should be kept dry and clean Where necessary i...

Page 12: ...ltifunction LCD display It interfaces to the headphones charger and microphone via military specification connectors Versatile leak noise sensing The acoustically shielded sensor mechanism provides is...

Page 13: ...s On Off and LCD backlight Low pass filters selection buttons Headphone volume control On Off Headphone button LCD display Gmic Controls The Gmic is simple to operate and has a limited number of contr...

Page 14: ...le the unit is on charge to see how much charge is in the batteries at any time However the Gmic MUST be switched back off again in order to resume charging When the unit is switched on the battery po...

Page 15: ...h itself off after 30 minutes of inactivity To switch the unit off the On off switch must be pressed and held down for a few seconds Headphones switch On Off The headphones can used switched on in two...

Page 16: ...ilter settings The low pass filter settings work in a similar way but with the ranges listed below The highest frequency that can be passed through the unit is 3kHz To reduce the frequencies passed Pr...

Page 17: ...z Low Pass 300 700 1500 2000Hz All Pass 0 3000Hz Band Pass Any combination of the above High Low settings 25 total Power supply 2 x Lithium ion 1 8Ah rechargeable batteries giving up to 50 hours opera...

Page 18: ...Foot Attachment Cast metal tripod for ground contact Hand Probe Attachment 2 stainless steel extension rods each 400mm in length Combined weight of rods 162g Headphones Lightweight robust high fidelit...

Page 19: ...rugged and shower proof to IP65 it contains electronic circuitry and should handled with care The equipment should be kept dry and clean Where necessary it should be cleaned with a damp cloth abrasiv...

Page 20: ...attempt to unscrew this sensor as this will break internal components of the microphone resulting in irreparable internal damage Sensor replacement is then the only option Any necessary repair or dism...

Page 21: ...acklit multifunction LCD display It interfaces to the headphones charger and microphone via military specification connectors Versatile leak noise sensing The high sensitivity sensor is enclosed withi...

Page 22: ...to be acoustically shielded from the surrounding environment either ambient noise or bad weather such as rain or wind The Rmic is especially suited for use on roads hence Rmic Road Microphone where it...

Page 23: ...z Low Pass 300 700 1500 2000Hz All Pass 0 3000Hz Band Pass Any combination of the above High Low settings 25 total Power supply 2 x Lithium ion 1 8Ah rechargeable batteries giving up to 50 hours opera...

Page 24: ...ht of rods 162g Headphones Standard Lightweight robust high fidelity headphones Optional upgrade to studio quality or aviation quality headphones Scope of supply Control unit Microphone foot unit with...

Page 25: ...ent at Palmer Environmental s option will be made without charge provided the above conditions have been met If any problems occur notify Palmer Environmental Ltd or its authorised representative givi...

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