Page 79: of Maritime Reporter Magazine (August 2018)

Prior to the start of the test, EUT op- erational status is determined to be in compliance. The EUT is then returned to its non-operational con? guration with no pressure and/or electrical energy ap- plied. With the EUT non-operational, the chamber temperature and humidity are adjusted to a temperature 55°C, with 90% Relative Humidity. This tempera- ture/humidity level is then maintained for a period of 2 hours, after which the

EUT is once again energized and its proper operation con? rmed. The cham- ber is then returned to lab ambient con- ditions/temperature/humidity and once again the proper operation of the EUT con? rmed.

• Voltage Variation

FIGURE 1 FIGURE 2

This test is performed to determine the ability of the EUT to withstand the ex- is performed at a rate suf? ciently low so el is maintained for a period of 2 hours. • Humidity pected stresses ue to simultaneous pow-

The purpose of this test method is to er ? uctuations in voltage and frequency as to permit resonance detection over a At this point the EUT is again ener- frequency range of 2 to 80 Hz. gized and its proper operation again con- determine the ability of the EUT to with- that may occur in use, and to ensure that

The typical rate for a resonance search- ? rmed. The EUT is then made non-oper- stand the expected stresses due to poten- performance degradations or malfunc- es is 1 octave per minute. Utilizing the ational, and the chamber temperature is tial high humidity conditions that can be tions will not be produced by such ser- data obtained (any resonant frequency(s) adjusted to 55°C. After this temperature experienced at in-service locations, and vice power ? uctuations environment.

in the resonance searches, the test engi- has stabilized, it is maintained for a pe- to ensure that performance degradations

For this testing the EUT is powered by neer will select the frequencies to per- riod of 2 hours after which the EUT is or malfunctions will not be produced in a programmable power source capable form vibration testing. (Resonant fre- once again energized and its proper op- such an environment.

of powering the EUT and producing the quencies are de? ned as response peaks eration con? rmed. For this testing the EUT is placed in- variations and transients shown in Table greater than twice the input accelera- The temperature chamber is then re- side the test chamber and setup in its op- 2. Prior to the start of the test, the EUT is tion amplitude). If no resonances have turned to lab ambient conditions/temper- erational con? guration with all the nec- place in its appropriate Mode of Opera- essary cabling connected and/or ? ttings tion and proper operation is con? rmed.

been found, the EUT will be vibrated ature, and once again the proper opera- at a frequency of 30 Hz with and ac- tion of the EUT con? rmed. engaged. (See Figure 2).

Proper operation is again checked at celeration of 0.7 g peak. Each resonant frequency dwell testing is applied for a minimum of a (4) hour period per axis.

During each 4 hour test the EUT is mon- itored for any physical or mechanical damage for proper operation in the mode of operation selected.

• Temperature – Environmentally Controlled Spaces

The purpose of this test method is to determine the ability of the EUT to withstand the expected stresses due to extreme temperature conditions at in- service locations, and to ensure that per- formance degradations or malfunctions will not be produced in such environ- ments. For this testing the EUT is placed inside a test chamber and setup in its op- erational con? guration with all the nec- essary cabling connected and/or ? ttings engaged. (See Figure 2).

Prior to the start of the test, EUT op- erational status is determined to be in compliance. The EUT is then returned to its non-operational con? guration with no pressure and/or electrical energy ap- plied. With the EUT non-operational, the chamber temperature is adjusted to 0°C and once stabilized that temperature lev- www.marinelink.com 79

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