TB 9-6625-2287-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Electronic Voltmeters, AN/URM-145 (ME-247/U) and AN/URM-145A (ME-
247A/U). The manufacturer's manual, TM 11-6625-524-15-1 and TM 11-6625-524-14 were
used as the prime data sources 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 indicated in text.
b. Time and Technique. The time required for this calibration is approximately 4
hours, 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 parameter and performance specifications which pertain
to this calibration are listed in table 1.
Table 1. Calibration Description
Performance specifications1
Voltage
Range
Test instruments parameters
ranges
accuracy
Frequency response
(V)
(FS)
10%
20
to
50 kHz
0.003 to 3
5%
50 kHz to
400 MHz
AN/URM-145 (ME-247/U)
5%
AN/URM-145A (ME-247A/U)
0.003 to 3
10 kHz to
200 MHz
1Verified
to 100 MHz for all systems codes except COO; for COO, verify to 400 MHz.
EQUIPMENT REQUIREMENTS
calibration procedure. This equipment is issued with Secondary Transfer Calibration
Standards Set AN/GSM-287 or AN/GSM-705. Alternate items may be used by the
calibrating activity. The items selected must be verified to perform satisfactorily prior to
use and must bear evidence of current calibration. The equipment must meet or exceed the
to-one ratio between the standard and TI.
5. Accessories Required. The accessories required for this calibration are common
usage accessories issued as indicated in paragraph 4 above and are not listed in this
calibration procedure.
