Applications of Davis Tube Tester
XCGS-ø50 magnetic tube is Davis analyzer tube and applies to laboratories involving coal dressing, mine,
metallurgy, geology, etc. The magnetic tube is used to measure the content of magnetic components in strongly
magnetic ores and provides reference data for separation of these ores.
Operating Principle of Magnetic Tube and Structure Introduction
Magnetic field intensity (GS): 2500(200KA/m) stepless adjustable
XCGS-φ50 Davis Tube: a glass tube is installed between the two poles forming electric magnet and moves and
swings reciprocally. When the separated material specimen passes through the magnetic field area, magnetic
substances are attached to tube wall, and non-magnetic substances are scoured by water and discharged during
2. Structure Introduction
XCGS-φ50 magnetic tube consists of principal machine and controller. The principal machine is shown in the
2.1 The bracket (2) is installed on the base (1) and used to support C-iron core (3) and exciting winding (10).
2.2 The connecting hoop (11) is installed at the magnetic pole end on the iron core and used to connect the driving
support (13). By loosening the nuts on the two sides of the hoop, the installation angle of the glass tube can be
adjusted and is generally 30°. After adjustment, tighten the connecting hoop (11) and install the nuts on the two
sides. Take care not to tighten them too tightly. Tighten them till the driving frame cannot be turned.
2.3 The glass tube (12) is embedded in the copper sleeve (8) and supported between the two magnetic poles via
the bracket. Hold the glass tube by hand and loosen the adjusting bolt (7). Then the glass tube position can be
adjusted. After it is well adjusted, tighten the bolt (7).
2.4 The motor (14) drives the glass tube to swing via the turbine (5), worm (4) and crank (6). The adjusting range
of the angle between the glass tube and horizontal line is 0°~40°. The travel of the glass tube is 40mm and its
swinging angle 45°.
1. Base 2. Pedestal 3. Iron core 4. Worm 5. Turbine 6. Crank 7. Adjusting bolt 8. Copper sleeve 9. Copper hoop 10. Exciting winding 11. Connecting hoop 12. Glass tube 13. Driving support 14. Motor
Field Installation of the Magnetic Tube Tester
As shown in Figure 2, install the magnetic tube:
1. Place the principal machine of the magnetic tube onto the bracket. Place the controller at an appropriate position
2. Turn off the power knife-switch and connect the cable of the controller with the motor, the cable (220V) of the
controller with the power supply and the line of the controller with the exciting coil.
3. Install the glass tube (5) onto the main frame and adjust the installation angle and position of the glass tube
4.Install the funnel, diversion hose, drain hose and tube clamp.
5.Place the bucket holder (11) at an appropriate position and mount the bucket (10) onto the bucket holder (11)
6.1.Firstly check all connecting lines and ensure no error. Then turn the machine by hand. All moving parts shall
run normally without collision.
6.2.Turn on the power knife-switch and “power start” switch. In case of any anomaly, immediately shut down
the machine, check for the causes and carry out commissioning again. In case of normal running, shut down the
machine and turn off power. Installation and commissioning are finished.
Attentions on Use and Maintenance of the Magnetic Tube Tester
1.When adjusting the glass tube, hold it by hand to prevent it from sliding down and damage.
2.Manually turn the machine before test run. After normal running, start the machine.
3.1.Oil feeding points in case of lubrication with machine oil:The crank connecting rod bearing, turbine and worm, guide frame,
hoop and torsional copper sleeve are oiled once a shift.
3.2.Oil feeding points in case of lubrication with grease:The grease of the worm bearing and motor bearing is replaced once every four months
Exciting Current and Magnetic Field Intensity Curve of Magnetic Tube
Carry out magnetic field calibration, record data and plot the curve of the machine prior to its delivery. See the
following table and Figure 3.
Table of exciting current and magnetic field intensity calibration
Figure 3 Calibration Curve of Exciting Current and Magnetic Field Intensity
Manual for Magnetic Tube Controller
The model of the controller is KDY-1. It is a manually adjusted controllable DC power supply and motor
controller and is dedicated to magnetic tube control
2.1 Output 1 DC<10A; Load>10Ω ，Output 2 AC 220V (controllable)
2.2 Volume 300x200x110
2.3 Power supply 220V
The terminal connection of the panel is shown in Figure 4. All the indicating meters and operation buttons of the
machine are installed on the panel.
Figure 4 Controller
3.1 Firstly connect 220V power supply
3.2 When starting measurement, turn the “power start” switch to “1” and adjust the “power adjustment” knob
(clockwise direction: current increase direction) to the needed current value. At this point the two ends of the
magnetic pole reach the needed magnetic field intensity.
3.3. In case of needing to start the motor, turn the “motor start” switch to “1”. Here the motor drives the
transmission mechanism and glass tube to work.
3.4. In case of completing the measuring work, turn the “motor start” switch to “0”. Here the motor is stopped.
Discharge the clear water in the glass tube.
3.5 In case of needing to discharge final magnetic substances, place a collecting vessel (no less than 500ml) at the
bottom outlet of the glass tube. Then turn the “power start” switch to “0”, cut off the magnetic field, slowly add
clear water from the funnel for washing, and completely discharge magnetic substances.
3.6 After completing the measurement, turn off the 220V power supply.
The machine is a wall-mounted instrument and can be hanged on any vertical surface. Wiring of the whole
machine must be strictly in accordance with the drawing
5.1 After work completion each time, turn the “power adjustment” knob to zero position. This prevents
components from being impacted and damaged during next startup. 5.2 “0” and “1” are marked on the “power
start’ button and “motor start” button. “0” means OFF, and “1” means ON.
Operating Instructions for Measurement of Magnetic Substance Content (recommended use）
1. Firstly check whether the power supply is normal, wiring is correct, the bucket contains water and the glass
tube position is very appropriate. Manually turn the machine and ensure that equipment runs normally
2. Weigh the mass m0=20g±20mg of the dried specimen (temperature no higher than 100℃ during drying). Place
the specimen into a 1000ml beaker, add an appropriate quantity of alcohol and about 500ml water, mix to
uniformity and let the beaker stand for about 5min. Ensure that particles are fully humidified during mixing.
3. After everything is all right, turn on the knife-switch and 220V power supply. Turn the “power start” switch to
“1” and adjust the “current adjustment” knob (clockwise direction: current increase direction) to the needed
current value. At this point the two ends of the magnetic pole reach the needed magnetic field intensity.
4.Magnetic field intensity is adjusted according to the magnetic intensity of magnetic substances and site
requirements for magnetic substances in general. It is suitable for the content of magnetic substances in the
collected specimen is 15g~20g in general. If there are very few magnetic substances in the specimen or the
magnetism of magnetic substances is weak, the magnetic field intensity shall be increased. Magnetic field
intensity can also be determined according to site requirements for the magnetism of magnetic substances.
Magnetic field intensity is adjusted to 150~220mT in general. Determine the needed current value referring to the
exciting current and magnetic field intensity calibration table or curve.
4. Turn the “motor start” switch to “1”. Here the motor drives the transmission mechanism and glass tube to work.
5. Tightly clamp the hose at the lower port of the glass tube using a tube clamp. Firstly add clear water into the
glass tube till the water level is about 50mm higher than the two magnetic poles (ensuring that the magnetic
substances added subsequently are suspended in water); then slowly pour the mixed liquid of magnetic substances
from the beaker into the funnel (the liquid level in the glass tube cannot be too high and is about 50m from the
funnel to ensure that the liquid doesn’t overflow from the upper port of the glass tube); meanwhile, open the lower
tube clamp of the glass tube, so that the liquid slowly flows into the 2500ml beaker.
The glass tube and the liquid in it are moving. After all the mixed liquid of magnetic substances is poured into the
glass tube, slowly add clear water (ensuring that magnetic substances are suspended in water). Non-magnetic
substances are settled with water flow till being discharged outside the tube. Magnetic substance particles are
attached to the two magnetic poles of tube wall under the action of magnetic force till the discharged liquid
doesn’t contain impurities
6. When the discharged liquid doesn’t contain impurities, stop adding clear water and tightly clamp the drain hose
using a tube clamp. Turn the “motor start” switch to “0”. Then the motor is stopped. Loosen the tube clamp and
discharge the clear water in the glass tube.
7. Place a clean and dried M0500ml beaker with its mass well weighed at the outlet of the glass tube. Then turn
the “power start” switch to “0” and cut off the magnetic field. Dismantle the glass tube and move it left and right.
Meanwhile, slowly add clear water from the funnel for washing, wash away the magnetic substances from the
glass tube and collect then into the beaker
8.Let the beaker containing the mixture of magnetic substances stand for about 15min till magnetic substances are
settled and the top water is clear. Then pour out the clear water and carry out drying (note that the temperature
doesn’t exceed 100℃ during drying).
9.Weigh the dried magnetic substances and the beaker to obtain the mass M. M-M0 is the mass of magnetic
10. Calculate the percentage content of magnetic substances:
β——–percentage content of magnetic substances
M——–total mass of pure magnetic substances and beaker, g
M0——-beaker mass, g
m0——- mass of the collected specimen, g
11.After completing specimen measurement, turn off the knife-switch and 220V power supply.