TB 9-6625-155-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Major Megger Insulation Tester, Biddle models 212159, 212160, 212359,
212459 and 212559, and Megger models MJ159, MJ359, MJ459 and MJ559. The
manufacturers' manuals were used as the prime data source in compiling these
instructions. The equipment being calibrated will be referred to as the TI (test instrument)
throughout this bulletin.
a. Model Variations.
Variations among models are described in text, tables and
figures.
b. Time and Technique. The time required for this calibration is approximately 1
hour, using the dc and low frequency technique.
2. Forms, Records, and Reports
a. Forms, records, and reports required for calibration personnel at all levels are
prescribed by TB 750-25.
b. Adjustments to be reported are designated (R) at the end of the sentence in which
they appear. When adjustments are in tables the (R) follows the designated adjustment.
Report only those adjustments made and designated with (R).
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 1.
Table 1. Calibration Description
Test instrument parameters
Performance specifications
Voltage
Models 212159, 212160, 212359, 212459,
Range: 0 to 600 V ac
and 212559
Accuracy: 1.75% fs
Models MJ159, MJ359, MJ459, and
Accuracy:
2.5% fs
MJ559
Range: 0 to 5000 Ω , 0 to 2000 MΩ
Models 212159, 212160, 212359, 212459,
212559, MJ159, MJ359, MJ459, and MJ559
Range: 0 to 1000 MΩ
Model 212160
Models 212159, 212160, 212359, 212459,
Accuracy:
1.25% FSD on 2.8 inch arc length (0.035 inches)
212559, MJ159, MJ359, MJ459, and MJ559
EQUIPMENT REQUIREMENTS
calibration procedure. This equipment is issued with Secondary Transfer Calibration
Standards Set, AN/GMS-286; AN/GSM-287; or AN/GSM-440. Alternate items may be used
by the calibrating activity when the equipment listed in table 2 is not available. The items
selected must be verified to perform satisfactorily prior to use and must bear evidence of