Sbe 29b Type Earth Resistance Meter

SBE29B Type Earth Resistance Meter Operating Manual
. Summar
SBE29B Type analogous earth resistance meter's features are complete function, high accuracy, easy to operate and work stably, with built in generator. It is suitable for the field application.It can be utilized to measure the earth resistance of the earthing system of the electric system, electrical equipment, communication tower, high-rise buildings and others.Moreover, it also can be utilized to measure the resistance value of low-resistance conductor and the specific resistance of the soil. Earth Resistance Meter is consisted of the hand generator, current transformer, slide-wire potentiometer, galvanometer and other parts.All components are installed in the plastic housing and the auxiliary probe and wire are put in the knapsack. It is very easy to carry the meter.The GB/T7676-1998 standard is applicable to the the ZC29B Type earth resistance meter.
.Specification, Performance and technical Index
1. Specification
Type(Ω)
Measurement range (Ω)(Ω)
Mini scale mark (Ω)(Ω)
Auxiliary earth resistance (Ω)%
Percent of accuracy (%)SBE29B-1
SBE29B Type0-100.1≤1000
≤100030-1001≤2000
≤200030-100010≤5000
≤50003SBE29B-2
SBE29B - type0-10.01≤ 50030-100.1≤1000
≤100030-1001≤2000
≤20003
2. Operating temperature and humidity : temperature (-20-40)ºC, relative humidity ≤80%.3. Testing temperature and humidity: temperature (23ºC±5ºC), relative humidity ≤75%.4. The rated speed of handle : 150 rpm.5. Influence of tilting : If the 5 degree tilting of any direction occurs to the meter , the variation of indicator value should be less than 50% accuracy.6. Influence of external magnetic field: If the magnetic intensity of external magnetic field is 0.4kA/m, the variation of indicator value should be less than 100% accuracy.7. The insulation resistance : The resistance value should be more than 30 MΩ.8. The dielectric strength: The insulation between the circuit and housing can withstand 1kV AC for 1 minute.9. The boundary dimension: L x Wx H(172x116x135) mm.10. Weight: 1.5kg(including the accessory)
Operating Instruction1. The requirements of using connecting wire, see the following table:A. Standard Configuration of connecting wire
Terminal(mm²)
Cross-sectional area (mm2)(m)
Length (m)(Ω)
Conductor resistance (Ω)E0.755< 0.13P0.7520<1
< 1C0.7540<2
< 2B.Two times measuring result of the connecting wire device:
Terminal(mm²)
Cross-sectional area (mm2)(m)
Length (m)(Ω)
Conductor resistance (Ω)E0.755< 0.13P0.7510< 0. 5C0.7520<1
< 1
2. Connection method (See figure 1)
potentiometer dialhandle multipliergalvanometergenerator handleFour connectorFigure 13.The measuring earth electrode E' is 20 meter (10 meter) away from the electric potential probe P' and 40 meter (20 meter) away from the current probe. The three probes' points should be in one line.The wire length of E terminal is 5 meter, P terminal 20 meter (10 meter), C terminal 40 meter (20 meter).The joint should be well connected , or the measuring result is not accurate.4. The it should place the meter horizontally and make certain that the galvanometer is at the zero position. If the galvanometer is not at the zero position, the zero adjuster canbe adjusted to the zero position.
5. It should turn the handle multiplier 2 to the max position, and rotate the generator handle 4; meanwhile turn the potentiometer dial 1 and make the galvanometer pointer 3 point to "0".6. When the galvanometer pointer is close to balanced, it should quicken the rotating speed of generator handle and make the speed 150 rpm and turn the potentiometer dial to make the galvanometer balanced. At this moment, the reading of the dial multiplies the multiplying power and the calculating result is the earth resistance value.If the wire length of E is 5 meter, P 10 meter and C 20 meter, the earth resistance value should be the two times measuring result.7.If the measuring earth resistance value is less than 1Ω, it should turn the ZC29B type earth resistance meter's handle multiplier to the minimal position (X 0.1), open the two connectors and connect a 5 meter (0.75mm2) to the measured objects so that the additional resistance resulted from the connecting wire resistance can be eliminated.,
8. If the galvanometer is too sensitive, the depth that dipolar probe are inserted into the soil should be shallowered; if the galvanometer's sensitivity is too low, it can inject the water into the soil around the probe.If there is the cement floor, the earthing probe should be placed horizontally, inserted into water and covered using the wet towel during measuring(the measuring error should be paid attention ).9. Measuring soil specific resistance(see figure 2)potentiometer dialhandle multipliergalvanometergenerator handleFour connector2Figure 2
A. The earth resistance meter with four terminal (1-10-100Ω, 0.1-1-10Ω) can be utilized to measure the soil specific resistance.B. The 4 probes should be buried in soil along a line and the distance between them is "acm". The setting depth of the probe should be less than 1/20 "a" distance.C. It should open two E connector and connected to the relevant probes by using 4 wires as indicated in figure 2. The measuring method is the same with the measuring earth resistance.The measuring specific resistance is P=2πaR. In this formula, R is the reading of the earth resistance meter(Ω).a: The distance (cm) P between probes : the soil specific resistance in that area.The specific resistance in the above figure can be regarded as the approximate average soil specific resistance between the probes.The measuring specific resistance is P=2πaR. In this formula, R is the reading of the earth resistance meter(Ω).a: The distance (cm) P between probes : the soil specific resistance in that area.The specific resistance in the above figure can be regarded as the approximate average soil specific resistance between the probes.
10. Measuring the conductor resistance and making certain that the meter is work normally (See figure 3)potentiometer dialhandle multipliergalvanometergenerator handleFour connectorFigure 3
A. The E and E terminal as well as P and C terminal should be short circuit for the meter with four terminal . The measured resistance should be connected to the position between E and P terminal.B. It should turn the handle multiplier to the correct position and rotate the generator handle at 150 rpm.It should turn the potentiometer dial and make the galvanometer pointer point to "0 " position. At this moment, the reading of the dial multiplies the multiplying power and the calculating result is the measured conduct's resistance value.C. Making certain the earth resistance meter works normally :It should connect the E and P using the two ends of one longest wire that is 40 meter (or 20 meter) and is one of the accessories( E and E as well as P and C are short circuit).And it should turn the handle multiplier to X1 position ( or X0.1 position) , rotate the generator handle at 150 rpm andturn ghe dial rotary knob to make the galvanometer pointer point to the "0" position. At this moment, the reading of the dial multiplies the multiplying power and the calculating result is the measured wire's resistance value( about 1Ω or 2Ω). If the result is the wire's resistance value, the meter works normally.Safety warning1. It is not allowed that the measurement is done if there are thunder and lightning or the measured object is electrified.2. The meter should be operated by qualified and trained staff and he or she should do the measurement strictly according to this manual.3. Our company will not take any responsibility for the damage of meter or personnel injury if the meter is misused or the measurement is not done in accordance with this manual or safety specification.4. The operator should read and understand the safety requirements in this manual and comply with them during using the meter.
Complete equipment1. earth resistance meter one pcs2. auxiliary probe two pcs3. wire 5m, 20m and 40m one pcs for each length4. Operating manual one pcs
5. product certificate one copy
6. knapsack one pcs
7. leather suitcase one pcs. Warranty1. The manufacturer shall repair freely the meter that can not work normally within the 12 month after shipment on condition that the user complies with the manual and requirements of storage and transportation.2. If the meter is damaged due to user's misuse or improper storage, the manufacturer will charge the reasonable repairing fee.