Electronic indicators
In 1983 LEHMANN & MICHELS GmbH manufactured their first electronic cylinder pressure measuring instrument and have since sold thousands of PREMET indicators (X series).
As we all know, technology continuously evolves and as a result we introduced the new PREMET C with colour display and extended features at the SMM in 2008.
We have now0 fully switched over to the new PREMET C. As a result we will phase out production of the ‘old’ PREMET indicators and from now on only quote and receive orders for PREMET C models.
Many of you are already familiar with the PREMET C, but for those of you who are not I have listed the main differences below:
- Colour display, which shows pressure curves and bar graphs immediately after taking the measurement
- Much larger memory which is able to store thousands of measurements (no need to store the data on a computer)
- If you want to upgrade your PREMET from e.g. C-LS to a C-XLMS, you do not need to buy a new PREMET. You just need to pay for a software upgrade.
- More robust devise - buttons no longer plastic, but stainless steel
- Data transferred via USB to PC without needing to install any software or drivers (like with a digital camera)
In comparison to the previous models the new PREMET C only costs a very little bit more ..
Some would call this an end of an era; however we consider it to be an exciting development to ensure our PREMET indicators maintain their reputation as a leading cylinder pressure indicator in the market.
Repair and service of older units
Please be advised that we still service, repair and calibrate older units such as PREMET L / PREMET LS / PREMET XL(H) XXL
Lemag PREMET C (New generation)
The LEMAG PREMET C is the latest generation of cylinder pressure indicators from LEHMANN & MICHELS GmbH. This new measuring instrument sets new standards and is based on almost 100 years of experience in cylinder pressure measuring and 25 years of experience with electronic indicators using the latest possibilities of electronics.
The most important element of the instrument is the cylinder pressure sensor. The latest generation of piezo electric sensors from Messrs. KISTLER is used in order to grant for highest possible accuracy and durability. The sensor is also designed for use over a long period of time with heavy fuel oil. Especially the new and comfortable control structure will be noticeable to the user. The high resolution colour display shows a detailed curve of the course of pressure and various statistic evaluations directly after the measurement has been carried out. The large integrated memory also enables hundreds of measurements and engine data to be stored in the instrument itself, clearly sorted and callable whenever needed. The modern heavy-duty battery also allows many measurements to be carried out before it has to be recharged. Evaluation of the data can be made either directly in the indicator or with a computer.
When the indicator is connected with a computer via the integrated USB interface all stored data can be evaluated immediately with a standard PC computer, without complex data transfer or software installation. Of course the stored data can also be sent by e-mail. An exact capture of the crank angle is necessary for an exact determination of the indicated power.
For intermediate and fast running engines either an inductive or a laser-based sensor is used, which sends the current crank angle to the indicator once per revolution. For slow speed engines the LEMAG MS („Multiscan“) sensor is available. With a physical resolution of only one degree crank angle, highest accuracy is guaranteed. The MS sensor is especially manufactured according to the shaft diameter of every vessel and it is installed firmly
In order to achieve a more exact evaluation of the engine condition, the unit can be extended by measurement of injection pressure, same as its predecessors. For this, an additional high pressure sensor is added and special high pressure valves are installed at each injection pump of the engine. The high pressure valves are certified by Germanischer Lloyd (GL).
For measuring on two stroke slow speed engines it is recommended to use an additional MS-sensor (multiscan sensor) which will be installed on the intermediate shaft close to the engine. This will optimise the accuracy because with the MS-sensor we are able to compensate the different angle velocity which affects the measuring results very much on two stroke engines.
It means on the slow speed main engine you measure with the permanent installed MS-sensor and on the auxiliary engine you measure with the single point TDCsensor.
The MS-sensor will be manufactured by us for the shaft diameter of your ship.
Please find an overview of the different LEMAG PREMET C versions and optional extras below:
PREMET C - scope of supply
LEMAG PREMET C - Base unit LS
electronic cylinder pressure indicator
complete, ready to use
for measuring peak pressure as well as course of cylinder pressure against time (p-max, p/t)
measuring range 0-250 bar
incl. charger, USB data cable and accessories
incl. analyzing software for Windows™
incl. certificate according to ISO 9001
delivered in waterproof service case
SDS/LEMAG part no.: 28040500
Extension module XL - for LEMAG PREMET C
extension oft the base unit for capture of crank angle with a TDC sensor
incl. 1 pc. Inductive TDC sensor with holder
incl. 2 pcs. TDC signal cables (1 x 10m, 1 x 40m)
extension of the software of the unit for analysis of compression pressure, medium pressure and indicated
pressure as well as crank angle related diagrams (p-comp, MIP, P-ind, p/alpha, p/V)
SDS/LEMAG part no.: 28040520
Extension module MS - for LEMAG PREMET C
extension of the base unit for capture of crank angle with multiscan sensor
incl. 1 MS sensor wheel with pick-up and holder – please advise shaft diameter
incl. 10 m MS signal cable
incl. 40 m MS signal cable with connecting box
extension of the base unit for processing incremental signals
requires extension module XL
SDS/LEMAG part no.: 28040530
Extension module fuel+ for LEMAG PREMET C
extension of the base unit for measuring course of injection pressure
incl. 1 pc. Injection pressure sensor 0 – 2.000 bar
extension of the base unit to a second measuring channel
extension of the software of the unit for capture of the course of injection pressure requires extension module XL
requires additionally one high pressure valve per cylinder
SDS/LEMAG part no.: 28040540
High pressure closing valve - for LEMAG PREMET C fuel+
high pressure valve for connection of the sensor to the injection pump
incl. connecting adapter
operating pressure range: 0 – 2.000 bar (test pressure: 2.800 bar)
incl. approval by Germanischer Lloyd (GL)
SDS/LEMAG part no.: 28042263
Furthermore it is also possible to optionally equip the PREMET C with a separate pressure sensor and flexible armoured wire. However, changing from the standard version to the version with a separate pressure sensor respectively from the version with a handheld sensor to the standard version is not possible.
optional:
Version with separate pressure sensor and flexible armoured wire
SDS/LEMAG part no.: 28040510
From the extension module XL onwards, there is one inductive TDC sensor with holder included in the scope of supply. For measuring further auxiliary engines further sensors are required:
1 pc. inductive TDC sensor
Complete, with cable and connecting box
SDS/LEMAG part no.: 28040027
1 pc. holder for inductive TDC sensor
SDS/LEMAG part no.: 28040017
