CM20 Electronic Chronometer

TYPE CM20 Swiss Chrono

2ATI Swiss Made Chronometer

The THOMMEN CM20 Electronic Chronometer is a 2ATI Swiss made precision chronometer designed to operate under the most stringend conditions in both civil and military aircraft.

 

 Main features

  • It utilizes solid-state Liquid Crystal Display (LCD) technology to provide a continuous readout.
  • It simultaneously displays the clock-and timer-functions and has several day/night mode backlight options including NVIS A and B compatibility.
  • The time function has a dedicated internal power supply to maintain the timekeeping function even when the aircraft power is removed.

 

Parameters

24 hour clock for UTC or Local Time (LT) in 12/24 hrs format
Up or down counting Elapsed Timer (ET/ETD)
Maintenance Timer (MTH)
Simultaneous display of Clock and either elapsed or night timer readings
Flight Timer (FT) with pre-settable alarm (FTA)
ETD and FTA with a common switching output for an external signaling device
Flight Timer (FT, FTA and MTH) remotely controlled by a configurable switch input
Remote setting functions via serial link (RS-232) in master and slave mode
Installer accessible installation feature settings
Installer customizable Lighting Dimming Curve for day and night mode
Lighting options (white/white, white/red, white/green NVIS A&B)
Comprehensive Built In Test with internal maintenance and failure log

PERFORMANCE SPECIFICATION

TIME BASE ACCURACY
better than ± 0.2 s / 24 h
MTBF
> 20.000 hrs. MIL-HDBK-217
LIGHTING OPTIONS FOR NVIS EQUIPMENT COMPATIBILITY
MIL-STD-3009 TYPE I CLASS B or RTCA/DO-275 or OST 1 00415-81

ELECTRICAL CHARACTERISTICS

SUPPLY POWER:
Nominal 14 or 28 VDC < 300 mA @ 28 VDC
Nominal 14 or 28 VDC < 300 mA @ 28 VDC
(CENTRAL INSTRUMENT PANEL DIMMING MODE SIGNAL)
0 to Supply Power Voltage sinks < 5 mA against power return
FT & MTH RUN SIGNAL:
0 to Supply Power Voltage sinks < 5 mA against power return
ETD & FTA ALARM OUTPUT SIGNAL
Solid state switch output sinking < 1000 mA against power return

ENVIRONMENTAL CONDITIONS

TEMPERATURE:
-55° C to +85° C ground survival and storage
-45° C to +70° C continuous operational
further options are available on request
COOLING
none
ALTITUDE
55.000 ft. for continuous operational and storage
further options are available on request
HUMIDITY
< 99% rel. humidity non condensing for continuous operational and storage

QUALIFICATIONS

RTCA/DO-160F:
[B2Z]BBB[U2]EWFSFSY[ZI]AZ[ZC](ZN)
[RR]M[A3H33]XXAC
MIL-STD-810F:
Method 514.5
Method 505.4 Procedure I
RTCA/DO-178B
Software Level D
RTCA/DO-254:
DAL D

MECHANICAL CHARACTERISTICS

FORM FACTOR
2ATI semi ARINC housing
L 62.0 mm (2.441 in) x W 60.3 mm
(2.375 in) x H 60.3 mm (2.375 in)
WEIGHT:
210 grams (7.4 oz.)
COLOUR
FED-STD-595 Housing black (37038) or
grey (36118)
Markings white (37875)
INSTALLATION:
Semi ARINC Housing installs using a metal mounting clamp
Connector Amphenol 71-570123-12-10
mates with MS3116E12-10S

MECHANICAL DRAWING

Installation & Operation Manual

Declaration of Design and Performance

User Operational Manual

Service Bulletins

No document available for this product.

Service Information Letters

No document available for this product.
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