How to troubleshoot loop resistance tester?

At present, conventional dual-arm DC bridges are commonly used in power systems to measure the DC resistance of transformer coils and the contact resistance of high-voltage circuit breakers. However, the test current of such bridges is only at the mA level, and it is difficult to find that the cross-sectional area of ​​the transformer coil conductive return conductor is reduced. Defects. When measuring the contact resistance of the high-voltage switch conductive loop, due to the influence of the oxide layer between the oil film and the moving and stationary contacts, the measured resistance value is a few times larger, masking the true contact resistance value. Therefore, the Ministry of Electric Power Standard SD301-88 “Transmission and Preventive Testing Regulations for AC 500KV Electrical Equipment” and the new “Preventive Testing Regulations for Electrical Equipment” shall make regulations for measuring the contact resistance of circuit breakers and disconnectors to not less than 100A to ensure that The accuracy of the measurement.

Technical Parameters:

Measuring range 100A0-19999uΩ

200A0-9999uΩ

Measurement Accuracy: 0.5 Display: Dot Matrix LCD Display Print Working Voltage: AC220V

Working principle: Sampling - Amplification - Hold - A/D conversion - Microcontroller processing - Output results: Display and print Outline: Compact chassis, power input socket and power switch in the lower part of the instrument

Technical indicators:

1. Measuring range: 0-1999μΩ Resolution: 1μΩ

2. Measuring current: DC100A (200A users choose to purchase)

3. Measurement accuracy: 0.5 level 4. Display mode: LCD display 5. Working temperature: -10°C～50°C

6. Working current: AC220V±10%

7. Volume: 490×320×240(mm)

8. Weight: 8kg


Failure analysis and exclusion

Cause of the malfunction Phenomena Remedy Remarks boot no display power is not on power should replace the fuse
Replace the same type of insurance
Cannot replace the instrument with other models 5A Fuse tube not installed or open circuit Re-installed fuse or replacement fuse The output current does not reach 200A The test line is too long that the cross-sectional area of ​​the wire is too small Replace the cross-sectional area Larger wire No current output Device to be inspected Open circuit inspection equipment
Troubleshooting The test circuit has an open circuit fault test circuit to eliminate open circuit faults

Petri Dishes

Sterile Petri Dishes from YongYue medical carries a complete line of contact plates, sterile, square (with a grid) and absorbent pad Petri dishes, cell spreaders and spatulas. Please contact us if you need additional product specifications. Two of our most popular lab dish products are standard petri dish and 3 compartment petri plate.
Sterile Agar Petri Dish
YongYue® petri dishes are offered in a variety of shapes and sizes for your everyday research needs. YongYue® manufactures optically clear plastic petri dish which are precision-molded from biomedical grade polystyrene for Cell Culture. Dishes are packed in heavy-wall polyethylene sleeves to ensure product integrity. YongYue® petri dishes have many applications including cell culture, growing bacteria and growing yeast.
Clear plastic disposable petri dishes of standard depth (15mm). Supplied in sterile packs. Will deform on autoclaving. Triple Vented. Also suitable for the temporary housing of small invertebrates during collection, or for distributing small chemical samples in class.
Diameter: 90mm
Depth: 15mm
Pack of 20

Culture Dish,Petri Dish,Petri Plate,Petri Dish Bacteria,Cell Culture Dish

Yong Yue Medical Technology(Kunshan) Co.,Ltd , https://www.yonyuemedicalcare.com