Rotary laser levels are made to layout grades in four different patterns or configurations.  The first obviously is to establish a flat plane over the earth’s surface.  Practically all rotary laser levels will help you set up grades in a flat, horizontal plane across a jobsite, or in the terms of interior lasers, across a room or building.

Single slope lasers, also called single grade lasers, will tilt on one axis to project a sloping plane.  An example of a sloped plane laid out on one axis would be for the construction of a continuous roadway grade, a tennis court or a vaulted ceiling in a room.

A dual slope laser, also called dual grade laser, will allow you to set grade along two axes.  A good example of this would be a parking lot that is graded in the X and Y axes to drain runoff to a catch basin in one of its corners.

The fourth type of layout pattern you find in rotary laser levels is a cone-shaped slope.  Cone lasers are essentially specialty lasers primarily used for sports fields.  Baseball fields for instance slope away from the pitcher's mound in all directions i.e. in a conical shape.  Agatec's CL185 Laser is a perfect example of a cone laser, which can be used for laying out a flat plane as well.

In addition to the above beam configurations is the way in which a level is designed in order for the user to engage its slope function feature.  There are primarily two ways that a single or dual grade level feature can be engaged and the first method is by doing "Grade Match."  Rotary levels that do grade matching, which are usually self-leveling or auto-leveling, must have the auto-leveling feature disabled before the grade matching feature is employed.  The level is manually tilted to the desired layout slope. As explained before, some lasers with grade match are single slope lasers and some are dual slope lasers.

The second method to engage a rotary laser's slope function is with "Grade Entry."  Grade entry allows the user to input the desired slope by punching the desired slope onto the laser's control panel or keypad.  Again, the auto-leveling feature will be rendered inoperative when this slope function is used.  This feature is a bell-and-whistle that will add to the cost of the laser, but it makes it very easy to use.

Johnson Level and Tool Company has just added four magnetic locators to its product line. The Johnson Magnetic Locators are used to detect ferrous metal objects whether they are buried as much as eight feet deep or hidden on someone's person. Search for a valve box lid hidden under asphalt, steel pipes used as property corners, downed fencing along a property line, or detect weapons for security screening. These magnetic locators are tough too. They can take being dropped from the truck onto the street or submerged in water as deep as 75 feet.

 The Johnson Magnetic Locators are really easy and very simple to operate. Model Numbers 40-6410 and 40-6420 both have a three-button keypad (see right). The middle button is the On/Off Power Switch as well as the speaker volume. The user controls the speaker volume by holding in the button causing the volume to cycle up to a higher volume until the button is released. The Gain Buttons control the sensitivity. The Gain Up Arrow increases sensitivity; the Gain Down Arrow decreases sensitivity. Operating the locators’ settings are as simple as that making single-handed operation possible.

The keypad for Models 40-6430 and 40-6440 is similar.  These two models have four buttons:  The On/Off Button, the two Gain Buttons (Up/Down Arrow), and a Zero Button.  The Zero Button is used to adjust the locator if a magnetic gradient soil strata produces a magnetic anomaly.  These two models do not have adjustable volume settings; rather, the volume fluctuates as a iron or steel object gets closer or further from the end of the detector.

Models 40-6420, 40-6430, and 40-6440 each have an LCD display like the one to the left. On the top of this display are two sets of bar graphs indicating Signal Strength and Polarity. Signal Strength bars will fill from the center out as the signal increase. Polarity bars will also fill from the center out as the polarity goes from negative to positive. A Gain bar graph in the lower left hand corner will fill in from left to right as the Sensitivity is increased by the user with the Gain Button and visa versa. A Battery Icon comes on in the lower right hand corner when the battery strength becomes low. That’s all there is to operate Johnson Level’s new magnetic locators.

The 40-6440 Long Magnetic Locator is ideal in aiding the user to keep him/her further away from any dangerous metal object. The 40-6430 Short Magnetic Locator is perfect for security screening and other situations where one handed, close operation is required. All models are lightweight, tough, and indispensable in the field for surveyors and engineers.