If possible, please provide only your telephone number to meet the needs of your local post office. If you are absent and cannot pick up items at your location in time, the post office may ask you to remind (in most cases, the postman will only give notice).
PS: We maintain a high degree of security and confidentiality of our customer's personnel information.
We mainly use EMS Express and Parcel Register Post for transportation. You can track EMS Express and your local post office. You can follow the post office at your local post office. Both require your signature to accept.
If you need a track number, please send us an email or leave us a message
We can also use other express transportation such as: UPS, DHL, FedEx, TNT etc. The cost will be higher. If you need the above services, you should contact us first.
Freight insurance is included in the S&H fee.
In general, EMS Express takes about 3 to 6 days depending on the location in the United States. Parcel post mail faster than EMS Express
If you do not use it at ordinary times, please contact us. We will first check its track number. If it does not work, we will send a paper tracking application to the USPS post office, which will take a few days to get a reply.
The principle of telescopic rangefinder and its key points of selection
Telescopic rangefinders usually use the pulse method to measure distance.The pulse method works as follows: the laser emitted by the rangefinder is reflected off the object to be measured, and is then received by the rangefinder, which simultaneously records the time of the laser round trip.Half the speed of light times the round trip time is the distance between the rangefinder and the object being measured.The accuracy of the pulse method used to measure the distance is usually about +/- 1 m.In addition, such rangefinders typically measure dead zones of about 15 meters.
Points of selection
1. The basic parameter of a telescopic rangefinder is to measure distance.First, you should choose a telescopic rangefinder that needs to measure distance.
2. Measurement accuracy. The nominal measurement accuracy of all manufacturers is +/- 1 meter, which is only theoretical data.The measurement accuracy depends on the target environment, telescope rangefinder lens, infrared laser emitter quality and data processor accuracy.
Detailed explanation of the operation method of laser rangefinder
Laser rangefinder usually USES two methods to measure distance: pulse method and phase method.
The pulse rangefinder works like this: the laser emitted by the rangefinder is reflected from the measured object and then received by the rangefinder, which records the time of the laser's reciprocation.Half the product of the speed of light and the time to return is the distance between the rangefinder and the object being measured.
The accuracy of measuring distance by pulse method is generally about +/-1 meter.Other, the blind area of this kind of rangefinder is about 15 meters.
How to use the rangefinder:
Firstly, arrange theodolite on the station, center and level it, place the main equipment of the rangefinder on the theodolite bracket, lock it with the fixing screw of the coupling, insert the battery into the bottom of the main engine and fasten it.Arrange the reflector at the policy point, center, level, and point the mirror toward the host.
Aim the center of the board with the cross thread of theodolite, and measure the perpendicular Angle alpha.Together, observe and record temperature and barometer readings.To observe the vertical Angle, air temperature and air pressure, the purpose is to correct the tilt, temperature and air pressure of the distance measured by the rangefinder, so as to get the correct horizontal distance.
Press the "PWR" key on the power supply to start the machine, the host will self-check and flash the original set temperature, pressure and prism constant value, and the self-check will flash "good" in the future.
To correct the set value, press "TPC" and enter the temperature, pressure or prism constant (usually through "ENT" key and digital key).In general, just use the same kind of reflector, the prism constant is the same, and the temperature and pressure may be different for each observation, which needs to be set from scratch.
Adjust the hand wheel (or theodolite horizontal fretting screw) and the pitch fretting screw of the main engine by scheduling the altimeter axis, so that the rangefinder telescope can accurately aim at the prism center. n the case of flashing "good", accurate aiming can also be judged according to the sound and motion of the buzzer. The stronger the signal is, the bigger the movement and motion is. The micro-moving rangefinder from left to right makes the maximum movement and motion of the buzzer.
Application field of laser rangefinder
Laser rangefinders are now widely used in the following fields: electricity, water conservancy, communications, environment, architecture, geology, police, fire, blasting, Marine, railway, counter-terrorism/military, agriculture, forestry, real estate, leisure/field sports, etc.