Hand Held Megohmmeter Model R1m-B
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R1M-B Revised August, 2004 HAND HELD MEGOHMMETER MODEL R1M-B Operation and Maintenance Manual PN# R1M-B-900-01 Publication Date: July 2012 REV. C TEGAM hereby grants to the U.S. Government a limited, non-exclusive, non-transferrable license to reproduce, scan and electronically store the manuals purchased by the US Government. This license shall remain in effect for as long as the equipment cited in the manuals remains under government control and usage, after which time this license is automatically terminated. NOTE: This User’s Manual was as current as possible when this product was manufactured. However, products are constantly being updated and improved. To ensure you have the latest documentation, refer to www.tegam.com 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] TABLE OF CONTENTS Revised August, 2004 TABLE OF CONTENTS 1. INSTRUMENT DESCRIPTION Purpose ............................................................... 1-1 Performance Characteristics ................................... 1-1 Description of Equipment ....................................... 1-1 List of Items Furnished .......................................... 1-3 Storage and Shipping Requirements ........................ 1-3 2. PREPARATION FOR USE AND INSTALLATION Unpacking and Inspection ...................................... 2-1 Preparation for Use................................................ 2-1 3. OPERATING INSTRUCTIONS General Theory of Operation ................................... 3-1 4. PRINCIPLES OF OPERATION 5. MAINTENANCE Inspection ............................................................ 5-1 Cleaning .............................................................. 5-1 Battery Replacement ............................................. 5-1 Calibration ........................................................... 5-3 Preparation for Shipment ....................................... 5-3 Overhaul Instructions ............................................ 5-3 Table 1: Parts List – Board Assembly .................. 5-4 Table 2: Vendor Cage Code Directory .................. 5-5 Figure 1: Input Circuit Schematic ........................ 5-6 Figure 2: Digital Board Schematic ........................ 5-7 Figure 3: High Voltage Supply Schematic ............. 5-8 Figure 4: Parts Layout ........................................ 5-9 6. SERVICE INFORMATION Preparation for Repair or Calibration Service ............. 6-1 Expedite Repair and Calibration Form ...................... 6-2 Warranty .............................................................. 6-3 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] INSTRUMENT DESCRIPTION Revised August, 2004 SECTION 1 INSTRUMENT DESCRIPTION INTRODUCTION 1.1 Purpose The Model R1M-B Megohmmeter is a compact portable instrument used to measure high resistance values, up to 200 MΩ. A voltage range is provided in addition, to permit measurements of circuits, which have voltage applied. Ranges are 1 to 200 MΩ for resistance, and 3 to 600 VAC RMS for voltage. It will also detect and display the presence of DC voltage; but can’t be used to measure DC voltage accurately. Test voltage is 500 VDC. The R1M-B is packaged in a high-impact housing designed to withstand the wear and tear of industrial applications. 1.2 Performance Characteristics This is a digital reading instrument. Ranges: Resistance Range: 1 to 199.9 MΩ Voltage Range: 3 to 600 VAC RMS Accuracy: Resistance measurement accuracy: ± (3% of rdg + 1 count) Voltage measurement accuracy: ± (5% of rdg + 1 count) Test Signal Accuracy: 500 VDC ± 10% 1.3 Description of Equipment Physical: A high impact plastic case is provided to contain and protect the instrument. A pouch is provided to contain and protect the instrument and test leads with their clips. The input terminals are insulated banana jacks for operator safety. Two 40” leads with probes and removable insulated alligator clips are provided. 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] 1-1 INSTRUMENT DESCRIPTION Revised August, 2004 Dimensions: 178 mm (7”) x 91 mm (3.6”) x 30 mm (1.2”). Weight is 0.6 lb (including the battery). Electrical: Power for the unit is supplied by a standard 9 V alkaline battery. With voltage present, the LED will stay bright (as long as the TEST pushbutton is depressed), and the R1M-B will display voltage and NOT resistance. Environmental: This unit will operate over a temperature range from 0 to 50 °C, 75% RH non-condensing, up to 3050 m altitude. Withstand functional shock of 40 G for 11 ms. Vibration: 20 G maximum at 5 to 55 Hz. Front Panel Controls and Displays A TEST pushbutton is the only control required, since the internal circuit makes all the decisions regarding function and range. A LED is provided to indicate that voltage is present on the DUT, and the R1M-B is in the voltage measurement mode. DISPLAY is a 3½ digit LCD, displaying readings from 1.999 to 199.9. The LCD with digits ½ inch high displays the voltage and resistance readings. A "LO BAT" legend comes on to indicate a low battery voltage. If the resistance is over 200 MΩ, the least three significant digits of the display will blank, indicating an over-range condition. TEST VOLTAGE Jack is recessed to prevent any accidental encounter. WARNING VOLTAGES AS HIGH AS 600 V MAY BE PRESENT ON THE TEST LEADS OR INSIDE THE CASE OF THIS INSTRUMENT!! DO NOT TOUCH ANY COMPONENTS WITH BARE HANDS OR WITH UNINSULATED PROBES! 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] 1-2 INSTRUMENT DESCRIPTION Revised August, 2004 1.4 List of Items Furnished 1 each Model R1M-B 2 Two test cables, over 40 inch long, with probes and detachable alligator clips 1 each R1M-B Instruction Manual 1 each Carrying Pouch 1.5 Storage and Shipping Requirements Standard precautions which apply to electronic test instruments should be followed. A hard mechanical shock, such as from dropping the R1M-B, could damage the LCD. Care should be taken to prevent damage to associated cables. The R1M-B should be stored in a relatively dust-free environment. Temperature: -40 to +71 °C. Relative humidity: 0 to 100%, non-condensing. Altitude: 4570 m See Section 5.5 below for shipping requirements. 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] 1-3 PREPARATION FOR USE AND INSTALLATION Revised August, 2004 SECTION 2 PREPARATION FOR USE AND INSTALLATION 2.1 Unpacking and Inspection Upon receipt, the R1M-B and accessories should be carefully unpacked and removed from the shipping container. Separate the units from the packing material and inspect both the instrument and the accessories for any external damage. If any dents, broken, or loose parts are seen, do not use the equipment. Notify the shipping company immediately and follow their instructions as to how to proceed. Check that all items are present. If any items are missing, notify the shipper if this is a new instrument. If not new, contact the previous user to locate the missing item(s). 2.2 Preparation for Use Remove the instrument and accessories from the pouch. If the battery has been removed, replace it, using the instruction listed in Section 5.3 below. If desired, screw the red and black alligator clips onto the probe ends of the test leads. CAUTION USE EXTREME CARE WHEN ATTACHING THESE CLIPS. HANDLE ONLY ONE CLIP AT A TIME AND HANDLE IT THROUGH THE RUBBER BOOT. 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] 2-1 PREPARATION FOR USE AND INSTALLATION Revised August, 2004 Connections to DUT Plug the banana plug ends of the test leads into the red and black banana jacks on the R1M-B. Connect the red alligator clip to one end of the resistor under test. Connect the black alligator clip to the other end of the resistor under test. When the megohmmeter is first turned on by operating the "TEST" button, the instrument automatically functions as a digital AC voltmeter, reading any voltage present on the test leads and displaying that voltage on the LCD display. At the same time, the "VOLTS" LED is on. If voltage is present, the instrument will not take resistance readings. However, if voltage is not present, the LED will dim or turn off (after the initial flash) and the meter will switch to the megohmmeter mode; the internal 500 VDC supply is connected to the test leads and the display reads MΩ. The button must be held in for several seconds to allow time for the 500 V and resistance readings to stabilize. As long as the TEST button is depressed, the instrument will continue to take readings. When the button is released, the power will automatically turn off to maximize battery life and to minimize the risk to the operator of being shocked by the 500 V across the test probes during resistance measurements. Note that the current is limited to less than 5 mA, but this is still enough to produce a shock. 10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110 • [email protected] 2-2 OPERATING INSTRUCTIONS Revised August, 2004 SECTION 3 OPERATING INSTRUCTIONS The R1M-B is designed for bench-top or field operation. 3.1 General Theory Of Operation A 2-terminal measurement method is used to determine the resistance of the item under test. The R1M-B calculates the resistance of the item under test utilizing Ohm's law and displays it on a 3 ½ digit display. Press the TEST pushbutton. If the test leads are connected to a "live" circuit, the "VOLTS" LED will come on and the digital display will read that voltage. Although the display is calibrated to read 3 V, if there is no voltage present, the R1M-B will automatically switch to the megohmmeter mode. The LED will dim, or turn off, after flashing momentarily, and the display will indicate the resistance across the terminals. With a new battery, the LED will get dimmer, if it shuts off completely; this is a sign of a weak battery. NOTE: Hold the button in for five seconds to ensure getting an accurate reading. If the resistance exceeds 200.0 MΩ, the three least significant digits of the display will blank.