KMS-2/Exia/Exd Transmitter
Installation and Operating Manual
Page 2 of 16 KMS-2:Exia/Exd IOM Rev H 18/05/10
ATEX
INTRODUCTION
The KMS-2 transmitter is a 4 to 20 mA loop powered transducer for measuring the level of liquid in a
vessel either directly (immersion application) using an annular float, or indirectly by mounting on a
magnetic level gauge.
The Exia intrinsically safe version can be used in all hazardous area zones when connected through an
approved isolation barrier.
The Exd Gb explosion proof version is suitable for Zones 1 and 2 (ATEX category 2 & 3) applications.
This transmitter is NOT intended to interface directly with Zone 0 areas. When used with Zone 0 tanks
etc (EPL Ga), the probe must be installed in accordance with IEC 60079-26 (i.e. in a separate ventilated
pocket and/or fed from an intrinsic safety supply)
The transducer consists of a stainless steel tube, containing the Magnetostrictive measuring element,
and an aluminium or stainless housing containing the electronic circuit board.
The unit operates by sending an electrical pulse down the sensing element; the resulting magnetic field
reacts with the field from the magnetic float to produce a return signal. The time taken for the return
signal to be detected enables a level measurement to be made since the precise velocity of the return
signal along the sensing element is known.
Output Signals
Analogue Output: The process variable and error status are transmitted over the current loop with values
as shown in table 1.
LCD Indicator: When fitted the display provides local indication of the process variable ranged 0-100% of
measured range. Additional error modes and calibration status as shown in Table 1
LED: Provide local indication during calibration when the optional LCD is not fitted.
Outputs
Mode Function ANALOGUE LCD (%) Zero LED Span LED
NORMAL Measuring 4-20mA 0.000/100.0 Off Off
Zero 4mA 0 On Off
Fixed Output Span 20mA 100 Off On
Start 12mA CAL Flash Flash
Zero set 12mA CAL On Off
CALIBRATION
Span set 12mA CAL Off On
Low level 3.5mA ERR.L Off Off
Return Pulse
Missing 23mA ERR.H Off Off
ERRORS Calibration
Failure 12mA CAL Fast Flash Fast Flash
Table 1
Instrument output status indication
The Low Level alarm must be enabled as shown in the configuration section. When set
the output signal will change to 3.8mA if the float drops more than 13mm below Zero
point.
