Search result for:  id10=WA 0812 2782 5310 Tukang Pasang Plafon Metal Berpengalaman Sumberlawang Sragen

The MetalMapper 2x2 is a specialized instrument used for the characterization and discrimination of UXO (unexploded ordnance). The instrument uses an array of transmitter coils and receiver cubes to measure the EMI (electromagnetic induction) response of buried Metal targets in the ground. Using software inversion algorithms, the data is used to discriminate targets of interest (TOI) from scrap Metal. Most Metal UXO larger than a 37mm projectile can be discriminated from scrap Metal. It can be difficult or impossible to discriminate smaller munitions like 20mm or small arms rounds. The MetalMapper 2×2 cannot be used for anti-tank or anti-personnel landmines, or for other UXO that is non-metallic. The MetalMapper 2×2 can usually detect all UXO targets of interest to depths of 60cm, and larger TOI to depths of 1m or more.

Hi Anton, We are not aware of any special grounding schemes for a large number of modules. In dealing with EMI interference, our experience is that you need to individually ground each Geode - how you do it depends on the conditions you are in, but generally a Metal stake with a wire to the grounding post is the best you can do. Sometimes adding a little water to the soil around the stake can help. We have seen a majority of this type of noise occur in highly resistive environments (dry sands or hard rock), and grounding can help. If you are able to orient the lines perpendicular to the transmission lines that can also help. In general, with high voltage lines, the emanating field (50 or 60Hz) is likely coupling into the spread cable. Each geophone pair in the spread cable is a big antenna, but the pairs are twisted so any signal induce in one will also be induced (in varying degrees) into its neighboring wire. This will lead to a common mode voltage at the input to each Geode channel. So it would depend upon the common mode rejection (CMR) of the Geode’s input amplifier to reject this common mode signal. But the CMR of an amplifier is finite, and if the common mode signal is large, the common mode range of a given channel can be exceeded leading to the 50 or 60 signal being amplified by the front end differentially resulting in a lot of noise. This can happen even with very good CMR. Also any unevenness in the spread cable pair twists will result in a differential signal which will be amplified by the system. We would also suggest trying the lower gain setting, in case the front end is being over driven. You may need a bigger source to overcome the loss of amplification, but if you can get data, even with substantial 50 60z noise, a post processing 50 or 60Hz filter may be able to clean up the record enough to be useable. We haven’t tried this, but if everything else failed then this might be worth trying: It is possible that the noise is being induced in to the coils of the geophones. If that’s the case, then putting a Metal can over the affected geophones might help. Note that the cans might have to be grounded with a Metal stake driven into the earth.

If you perform a land magnetometer survey and you see random spikes in the data spread out over many cycles, these being real magnetic events, then the issue might not be the sensor but Metal on your person. A baseball cap often has a little steel button on the top, and for land magnetometers where the sensor is overhead, this steel is very close to the sensor. With movement during walking, this can create strong magnetic spikes in the data. To test this, you can mark the location of the magnetic sensor in relation to the steel button on a baseball cap and record the magnetic field standing still. Then lower the sensor 1 meter and you'll observe the anomaly increase by a factor of 16 or so. For magnetometer surveys, it is important that the operator is free of electronics and Metal. This means no cell phone, no belt, no steel toe boots, etc. Small quality checks can have a big impact on the data and save time in the field.

The cesium used in our magnetometers is the non-radioactive elemental Metal, isotope Cs 133. We employ approximately 120 to 240 micrograms of cesium Metal in the sensor divided between the lamp and absorption cell. These are small glass ampules, each containing a volume of 1/32 to 1/16 of a cubic millimeter of cesium. If either or both the lamp and cell should break the cesium will instantaneously react with the air and moisture in the air to become Cs2O and/or CsOH. Both compounds are caustic but the quantity is so small that it is of no health concern. Finally, the lamp and the cell ampules are contained in a G10 housing that is then contained inside a sealed PVC housing. If the sensor should cease working due to a broken lamp and/or cell, it is not field repairable. Return the sensor to Geometrics for repair, replacement and/or disposal.

Regarding the deployment of magnetometers on conductive sleds or carts near power lines: Depending on the proximity of the magnetometer to the sled, elevated field readings may be observe under power lines are a result of AC induction in the aluminum sledge you are using as the tow vehicle. The reason there can be a DC effect from an AC source is due to 1) the strength and proximity of the induced AC source and 2) the orientation of the induced AC field relative to the Earth's field (DC). Our cesium-vapor magnetometers measure the total local field continuously but report these measurements periodically, e.g at 10, 1000 times per second. For each reporting period, both the AC and DC components of the total field are integrated to produce the measurement result as a time average over the measurement cycle. If your measurements are being reported 10 times per second (10 hz sample rate) and the AC component of the field is 50 hz, then each measurement will include exactly 5 AC cycles. This AC component will add to the DC component as a vector sum and the magnetometer will measure the magnitude of the resultant vector. Note that the vector component of the 50 hz AC field that is parallel to the DC component will not contribute to measurement results: for half of each AC cycle this field is greater than the DC field and for the other half of the cycle it is less than the DC field by an equal value. This is not the case for the AC vector component that is perpendicular to the DC field: it will be adding magnitude to the DC field on each 1/2 cycle to produce a half-wave-rectified wave form. Specifically, this rectified field will add to the DC field by an amount equal to about 35% of its peak-to-peak field strength in the direction perpendicular to the DC component. The AC rectification described above is only seen on close approach to very strong AC sources (high tension power lines). An aluminum sled can act as an indirect source of the AC fields: the radiated 50 hz field from the power lines is inducing 50 hz eddy currents in the sled and, if a magnetometer is in close proximity of the sled's aluminum plates, it will detect large AC field values. Note that surveying near other large, planar conductors under the high tension power line can produce a similar effect. These would include Metal buildings, Metal fences, and pipelines. We recommend constructing magnetometer sleds from non-conductive materials. If this is cannot be done, then conducive materials should be kept as far from the sensor as is practical and the sled's construction should not include sheets of conductive materials. Any joints between conductive structural elements should be insulated as well. You can use the magnetometer itself to measure the effect of the sled.

This is for customers of the ATOM 1C and ATOM 3C seismographs (“ATOMs”) and is intended to provide guidance on ways to improve the download behavior via Wi-Fi. The ATOMs should be removed from any enclosure and positioned with the Metal base plate down and relatively close to the Access Point (AP), which will increase the signal strength available to both the Atom’s and the AP. The RF environment during data download can impact whether the ATOMs can connect and on how fast they download data. Other RF devices in the vicinity (i.e., Bluetooth, wireless cameras, other APs, etc.), can cause slower download time. If there is a microwave oven operating nearby, this can disrupt communication between the ATOMs and the AP. If you are having trouble getting the ATOMs to connect and download, try setting up the AP and laptop and then turning on the ATOMs one-by-one waiting for it to connect before turning on the next unit. Another thing that will improve download performance is connecting the laptop directly to the AP with an Ethernet cable. This eliminates all of the RF traffic between the laptop and AP. Summary: *Choose a location with the least amount of RF traffic. *Remove all ATOMs from any enclosure and place each ATOM on its aluminum bottom base plate. This is the best position for the internal antenna. *When possible, everything should at least be on the same level, off the ground, on a desk or table. The AP can even be placed higher than the ATOMs. *Each ATOM should have at least a foot of space around it and be within 10 to 12 ft. of the Access Point. Being too close to the AP is also not ideal. *The ATOMs and AP should be in the same space or room with the AP being centrally located. *Connect the Access Point directly to the Laptop with an Ethernet cable rather than using a WiFi connection between the laptop and AP. *The Access Point can connect up to 30 devices at once, but it is advisable to connect 24 or fewer. The time it takes to connect will vary from ATOM to ATOM. If after 1.5 minutes an ATOM is not found, restart the ATOM. If after another 1.5 minutes an ATOM is still not connected, it could be a hardware issue. Contact support@geometrics.com Download time may also vary from ATOM to ATOM. If an ATOM disconnects or takes a much longer time than other ATOMs to download (>30 minutes) it could be a hardware issue. Contact support@geometrics.com

The MetalMapper 2×2 measures in two distinct modes. A dynamic survey involves collecting data over the site while the instrument moves in a series of parallel swaths. The dynamic survey then identifies targets which need further characterization. These targets are then measured during a static or cued survey, where the instrument makes measurements while stationary over the previously identified targets. In clear areas with a trained 2 man crew, the MetalMapper 2×2 can survey about ¾ of an acre per day in dynamic mode or collect 200 cued targets per day in static mode. It is not practical to use the MetalMapper as a Metal detector for applications like prospecting or utility location due to the specialized nature of the measurement and the instrument cost.

Total field magnetometers like the optically pumped cesium magnetometer are passive devices, they do not send out waves or pulses. They measure distortions in the earth’s normally homogenous magnetic field and can sense distortions due to ferrous objects at great distances. The basic rule of thumb is that one ton (1000 Kg) of steel or iron will give us a 1nT anomaly at 100 ft. or 30m. Since the amount of distortion falls off as the cube with distance (compare a Metal detector which falls off as the inverse 6th power!) and is linear with mass, every time we cut the distance in half, we can see 1/8th the mass. Therefore, we can sense 250 lbs. (100kg) at 50 feet (15m), or 30lbs (15kg) at 25 feet (8m), or 4lbs (2kg) at 12 feet (4m). However this is not the whole story. The factors given above are for induced magnetic fields only. Many targets also have remnant or permanent magnetic effects (meaning they have become magnetized either in production or by the earth’s field) and can therefore have larger anomalies by a factor of 3 or 5 or more. Also many hollow objects like barrels or other tubular structures appear as though they are solid due to self-shielding from the earth’s field, and thus have much larger anomalies than their mass would predict alone. Pipes fall off as the inverse square and are thus detectable at even greater distances. Please see our Applications Manual for Portable Magnetometers for more information.

A common question many have with magnetic surveys is "How wide of a survey swath does a single magnetometer sensor cover on a single pass?" The answer is it depends on what is being searched for. Magnetometers are passive instruments, meaning they don’t actively send out signals or have a limited swath or depth of exploration. When planning a magnetic survey the grid (line spacing and waypoint spacing) should be designed using the best possible model of the target. There are some general rules of thumb that can be used to determine typical detection ranges for common iron objects. For example, a 10lb sledgehammer has been lost and needs to be found, and assuming this is 10lbs of pure iron, it would be expected to see a 1nT anomaly when the magnetometer sensor passes 6 meters over the top of the tool. Knowing this, survey line spacings should not be any narrower than 6 meters. With a line spacing of 3 meters, the chances of getting a clear anomaly goes up 8 fold as the 10lb iron sledgehammer would be at a minimum a 8nT anomaly vs a 1nT anomaly. In a geological sense, let's say we have a mafic dike intrusion that we believe is running E-W and it extends at least 25 meters in the near-surface in a somewhat linear fashion. It's difficult to model the amount of iron in a geological structure like this, so the survey should be designed to cross the dike perpendicularly every 5 meters or so, making sure to cross over the dike several times. Each pass over the dike may exhibit an anomaly of similar amplitude, and the feature will show up as a clear linear feature in the final processed map. For general mapping of geology, you have a lot of options. Most commonly mineral exploration surveys are done over very large areas, so the line spacing is wider to save time as the lower resolution model that results still accomplishes the task of finding large mineral deposits. If more detail is required, then a more fine-grained survey can be done later. 20m-50m line spacing is typical for mineral exploration surveys. Design a survey grid to completely encompass the area of interest (i.e. make sure you get some data outside of the areas of interest, in case an interesting anomaly lies right along the edge). The founder of Geometrics the late Sheldon Breiner called this the Law of Search, as he often found his targets of interest along the edges of his archaeological magnetic surveys. It is important to make sure the operator of the magnetometer is magnetically clean before surveying with the magnetometer. This means no steel toe boots, glasses or hats with Metal fittings, cellphone, belt buckle, etc. Magnetometer data acquisition is fairly simple, but data interpretation can be complex. You may need a base-station too. Please refer to the Base-Station information.