Electrophysics MOISTURE METER MODEL CT858 Electrophysics Box 310, Dutton, Ontario N0L 1J0, Canada Phone or Fax: (519) 768-2146 www.electrophysics.on.ca OPERATING INSTRUCTIONS & INFORMATION NOTES ZERO AND CALIBRATION INSTRUCTIONS: MODEL CT858 FIRST: CHECK THE ZERO POINT AND RE-ADJUST IF NECESSARY AS FOLLOWS: Turn the meter off then on again after a few seconds, to reset. Now set the density to “00” (the main instructions tell you how to push the “menu” and “scroll” buttons to do this) and leave the meter turned on until zero and calibration are done. On the body of the sensor probe casing there are two small white plastic screws. Remove the screw giving access to the zero adjustment (see photograph below). A small brass screw will be visible through the exposed hole. Hold the sensor probe in mid-air with the sensor pad well away from any material objects, and with a small flat-bladed screwdriver slowly turn the brass screw until the meter reads “00”. Re-insert the white plastic screw now, to avoid later confusion. CALIBRATION ADJUSTMENT There are two plates. Place the copper-coated plate on a table top or other convenient flat non-metallic surface, with the copper side facing down. Place the clear plastic plate on top of the copper plate. Set the density to 0.50 and place the sensing pad directly on the top plate and press gently. The meter should read 14%. If it does not, proceed as follows. Remove the white plastic screw in the sensor pad casing, which gives access to the calibration adjustment (see photograph below). A small brass screw will be visible through the hole. With a small flat-bladed screwdriver turn the brass screw extremely slowly until the meter reads 14. Re-insert the white plastic screw to keep foreign materials out of the sensor probe. It is important that the copper coating on the calibration plate be kept flat, clean, smooth, untarnished and uncorroded, and the clear plastic plate should also be clean and smooth. ACCESS TO CALIBRATION ACCESS TO ZERO ADJUSTMENT SCREW ADJUSTMENT SCREW HOLD THE SENSOR UNIT ONLY AT THE CABLE END KEEP FINGERS WELL AWAY FROM THE SENSOR BLOCK 15 WOOD MOISTURE CONTENT CHART MOISTURE METER MODEL CT858 WOOD MUST BE DRIED TO THE CORRECT MOISTURE CONTENT FOR OWNERS MANUAL THE INTENDED PURPOSE HOW TO GET THE MOST FROM YOUR MOISTURE METER Congratulations on your purchase of an Electrophysics high precision quality RELATIVE HUMIDITY % MOISTURE CONTENT MC % moisture meter! Please take the time to read these pages of information. The moisture meter is a sensitive and quite sophisticated electronic device. When WOOD PRODUCTS IN WOOD PRODUCTS IN USE not in use it should be stored in a dry place, preferably indoors at room MANUFACTURING temperature. Undue heat, cold, or excess humidity can all damage (or at least 25 MARINE PILING affect the accuracy of) even the quality components used by Electrophysics. 24 BASIC OPERATION 95 Your meter is shipped with batteries already installed. To turn on the Model 23 PRESSURE TREATMENT CT858, turn the rotary switch one click clockwise. A second click clockwise will 22 also turn on the display light and the audible beeper alarm. The sensor pad is the black block about 1.2 x 1.5 inches at one end of the 21 sensor probe, which is connected to the meter by a cable. To make a moisture 90 20 RAILROAD TIES content measurement, hold the sensor probe casing with the fingertips as far removed as possible from the sensor pad, and press gently against the sample MAX MC FOR AIR OR KILN 19 DRIED LUMBER (NLGA) to be measured. Ensure that the sensor area is closely in contact with the sample, and that the entire sensing area is fully contacted. 85 18 STOCK FOR BENDING The digital liquid crystal display (LCD) will indicate the moisture content directly 17 as a percentage. Each time that you turn on the meter, it powers up with standard or default 80 16 TYPICAL MC FOR settings of 0.5 for wood density and 1.5 inches for wood thickness. You can CONSTRUCTION LUMBER, 15 PRESERVATIVE TREATMENT UTILITY POLES change these settings easily in a few seconds by pushing the appropriate OF UTILITY POLES, BRIDGE buttons, and this is described as a step-by-step procedure in the following 75 14 TIMBERS, etc paragraphs. If you are working with wood, please remember to actually set the wood density to the correct value for your species, because the density 70 13 BOXES & CRATES, BOAT corrections may be quite large. If you are working with non-wood materials FRAMES, DECKS, please refer to the separate booklet for suggested settings and procedures. The 65 12 PLANKING, GARDEN FURNITURE, meter consumes a considerable amount of power, especially when the LCD LUMBER FOR GLUED & FARM IMPLEMENTS, illumination is turned on, so remember to turn it off after use. The batteries will 60 11 LAMINATED BEAMS TRUCK BODIES last very much longer when the meter is used intermittently rather than being 55 10 left on for long periods of time. SPORTING GOODS 50 9 SETTING THE WOOD DENSITY LUMBER, JOISTS, STUDS Below the LCD display (inside two circular cutouts in the red front panel) are two 8 colored lights which you will see illuminated at various stages while you are 40 changing the meter settings. Below the two lights are two pushbuttons. To 7 PLANING & TURNING change the density setting, press and hold down the left (“menu”) button until 30 6 FLOORING, SASH & the left light is red, then release the button. The display now shows the current DOORS, MILLWORK, density setting in grams per cubic centimeter. Find the density of your wood VENEER FOR LAMINATION FURNITURE, MUSICAL 5 & PLYWOOD sample in the table provided (see later pages). Now push and hold down the 20 right-hand (“scroll”) button. You will see the displayed density change or scroll 4 step by step through the available density values. Release the right button when 15 you see the desired density. The meter is now set for the selected value. Push 3 10 and hold down the left button again until no lights are illuminated, and the 2 meter is ready to use (in sequence, you will see the left light turn green, then go 5 out, then the right light will be green, and then go out). 1 SETTING THE WOOD THICKNESS 0 OVEN DRIED WOOD For wood samples less than 1.5 inches thick, readings can be corrected as 14 3 follows. Push and hold down the left button until the left light is green, then release the button. The display now shows the wood thickness in inches for MOISTURE CONTENT & HUMIDITY which the meter is set. To change this value, push and hold down the right button until you see the desired thickness, then release the button. Now push and hold down the left button until no lights are illuminated, and the meter is ready for use (you will see the left light go out, then the right light green and then go out). SETTING THE PERCENTAGE LEVEL ALARM Push and hold down the left button until the right light is green, then release the button. The display now shows the current alarm setting (99% each time the meter is turned on). To change the alarm level, push and hold down the right button until you see the desired setting, then release the button. Push and hold down the left button again until no lights are on, and the meter is ready to use. For the Model CT858, the beeper sounds in addition to the right-hand light appearing red. The alarm feature is handy for quickly scanning in a “go or nogo” situation, such as accepting or rejecting large amounts of wood in a delivery, or looking for unacceptably moist wall or ceiling areas during building inspections. ZERO ADJUSTMENT Normally the LCD display should show 0% when the meter is turned on and the The curve above left shows the approximate relationship between relative humidity (RH) and sensing pad is held in mid-air, well away from any material object. equilibrium moisture content (EMC) for most woods. At the right the curves show the seasonal indoor variation of moisture content in wood. “A” is unfinished veneer or wood However, under extreme combinations of temperature and humidity, and as surface. “B” is furniture of kiln-dried lumber, well coated with finish. “C” is furniture or air- ambient conditions change in your workshop, or as the meter is carried from dried lumber, well coated with finish. one location to another, and as the meter ages, the zero-point setting may drift slightly. A reading within plus or minus 1% of the zero mark is normal and Below left the table gives typical shrinkage % for various species. The wood most likely to acceptable, and will not affect the accuracy of your readings. warp has the highest T/R ratio. If the zero point needs to be reset, you can do this easily and quickly. All you need is a small flat-bladed screwdriver, readily available for example in “eyeglass repair” kits. See the step-by-step instructions on the inside back cover (page 15). CALIBRATION ADJUSTMENT The meter electronics are very stable and for most users there will never be any need to worry about the calibration, unless there is an accident of some kind which might upset the internal adjustments. For greatest security and peace of mind, you can check the calibration at any time, and if necessary fine tune the meter using the calibration plate included with your meter.