Nine problems in the use of infrared thermometer to pay attention to
In the use of electronic pounds in the role of infrared thermometer is omnipresent, because the resistance strain infrared thermometer itself is a strong, durable, reliable electromechanical products, but in order to ensure the accuracy of the test, but the electronic pounds in the use of the problems to be noted, then the use of infrared thermometer should pay attention to what matters? The following describes some of the infrared thermometer use must be noted to the nine aspects of the problem:
1, infrared thermometer should try to set up around some of the "baffle", or even with a thin metal plate to the thermometer cover up.
This can prevent debris staining pyrometer and some movable parts, and this "staining" will often make the movable part of the movement is not happy, and affect the weighing accuracy. Whether the system has the movement of the phenomenon, you can use the following methods to identify. That is, on the scale plus or minus about one-thousandth of the rated load to see if the electronic weighing scale weighing display instrument is reflected, reflected, indicating that the movable part is not "tainted.
2, all leads to the display circuit or lead from the circuit, should be shielded cable.
Shielded wire connection and grounding should be reasonable. If not grounded through the mechanical frame, then grounded outside, but the shielded wires are connected to each other not grounded, is floating.
Note: There are three pyrometers are fully parallel connection, the pyrometer itself is 4-wire, but in the junction box for 6-wire connection. Pyrometer output signal readout circuit should not be able to produce strong interference with the device can be "silicon, contactors, etc.) and there is considerable heat generated by the equipment in the same box, if you can not guarantee that this point, it should be considered to set up a baffle between them to isolate it, and in the box placed in the body of the fan. Used to measure the output signal of the pyrometer electronic circuit, should be configured as far as possible independent of the power supply transformer, and do not share the same main power supply and contactors and other equipment.
3, infrared thermometer should be used hinged copper wire (cross-sectional area of about 50mm2) to form an electrical bypass to protect them from welding current or lightning hazards. Pyrometer use, must avoid strong thermal radiation, especially unilateral strong thermal radiation.
4 The temperature measuring instrument must be prepared in terms of electrical connection (e.g. the signal cable of the temperature measuring instrument is not arranged in parallel with the strong power or control lines (e.g. don't put the signal line of the temperature measuring instrument and the strong power and control lines in the same pipe). If they must be placed in parallel, then, the distance between them should be maintained at more than 50CM, and the signal line with a metal pipe sleeve.
5, as far as possible, the use of automatic positioning (reset) role of the structure of the accessories, such as ball bearings, joint bearings, positioning fasteners.
They can prevent some lateral force acting on the pyrometer. It should be noted that some lateral forces are not caused by mechanical installation, such as lateral forces caused by thermal expansion, lateral forces caused by wind, and lateral forces caused by vibration of agitators on some container scales, i.e., they are not caused by mechanical installation. Some scales must be connected to the scale body on some attachments (such as container scales feeding pipes, etc.), we should let them in the direction of the thermometer loading spindle as soft as possible, in order to prevent them from "eating" the thermometer's real load together and cause errors.
6, to take lightly put especially by the aluminum alloy to make elastomers of small-capacity pyrometer, any impact, fall, on its measurement performance may cause great damage. For large-capacity infrared thermometer, in general, it has a large self-weight, so the requirements in the handling, installation, as far as possible, the use of appropriate lifting equipment (such as hand-operated hoist, electric hoist, etc.). Installation of the thermometer base mounting surface should be flat, clean, without any oil film, adhesive film and so on. Installation of the base itself should be sufficient strength and rigidity, generally require higher than the strength and stiffness of the pyrometer itself.
7, although the infrared thermometer has a certain overload capacity, but in the weighing system installation process, should still prevent the thermometer overload. It should be noted that even a short period of overload may cause damage to the pyrometer.
During installation, if necessary, the pyrometer can be replaced by a pad of the same height as the pyrometer, and then, when it arrives, the pyrometer can be replaced. In normal operation, the pyrometer should generally be set up to protect the mechanical structure of the overload. If the thermometer is fixed with a screw, a certain tightening torque is required, and the screw should be screwed into the thread depth. Generally speaking, the fixed screw should be a high-strength screw.
8, regardless of the circumstances, the power line and the control line should be twisted together, the degree of integration of 50 rpm / m, if the thermometer signal line needs to be extended, it should be a special sealed cable junction box. If you do not use such a junction box, and the use of cables and cables directly to the butt (tin soldering end), it should be sealed to pay special attention to moisture, connected to the insulation resistance should be tested, and need to meet the standards (2000 ~ 5000M), if necessary, should be re-calibrated pyrometer. If the signal cable is very long, but also to ensure a high degree of measurement accuracy, should be considered with a relay amplifier cable compensation circuit.
9, horizontal adjustment
There are two aspects of horizontal adjustment. One is a single pyrometer mounting base installation plane to adjust the level of the level meter, on the other hand, refers to more than one pyrometer mounting base mounting surface to try to adjust to a level surface (with a level meter), especially the number of pyrometers more than three weighing system, more attention should be paid to this point, the main purpose of doing so is to make the load borne by the pyrometer is basically the same. The loading direction of each kind of electronic weighing infrared thermometer is determined, and when we use it, we must load the load in this direction. Lateral forces, additional bending moments, torque forces should be avoided as much as possible.
