Tel: 215-355-6900
www.ametekpmt.com
Model 88
Features
A miniature, low-• priced, full-featured transmitter—
just 1.67 lb.
• All welded 316 stainless steel construction
and wetted parts (no aluminum)
• Ranges from 0 to 3 to 0 to 5000 psig
(0 to 0.2 to 0 to 350 bar)
• ±0.25% accuracy
• Zero and span adjustability
• Full 5:1 range turndown
• Integral junction box
• FM and CSA explosion-proof and intrinsically safe
• 4 to 20 mA output at 12 to 40 VDC
• 5-year warranty
• CENELEC-approved version available
Operation
The heart of the Model 88
pressure transmitter is a silicon
piezoresistive sensing chip. This miniature microetched
semiconductor gives a voltage output proportional to the
applied pressure. The chip is isolated from the process
media by a stainless steel diaphragm. A silicone oil or
other specifi ed fi ll fl uid is used to transmit the process
pressure to the sensor.
An amplifi er PCB enclosed in a sealed chamber is
used to convert the millivolt signal from the sensor to a
calibrated 4 to 20 mA transmitter output. Feedthroughs
for EMI and RF protection are used between the amplifi er
board and the terminal housing.
Each transmitter is tested over both pressure and
temperature ranges. A compensator circuit is used to
bring the output of the sensor into specifi cation. After
compensation, every transmitter is tested a second time
for pressure and temperature effects to ensure that it
meets performance and specifi cations.
Description
The Model 88 is the most durable, accurate and costeffective
pressure transmitter presently available. A fullfeatured,
all stainless steel transmitter, it is designed
for years of stable performance in even the toughest
environmental and media conditions. Approvals include
FM and CSA for both intrinsic safety and explosion-proof
ratings. CENELEC approval for intrinsic safety available.
The Model 88 also meets NACE standards for offshore
applications. A fi ve year warranty is standard for the 88C.
The small size and light weight of the Model 88
transmitter eliminates the need for complicated mounting
hardware and mechanical supports, thereby reducing
installation time substantially. The integral junction
box permits simple field wiring without the need for
additional hardware, adding to the speed and ease of
installation.
A 4 to 20 mA output is standard with a 12 to 40
VDC power supply. With all 316 stainless steel welded
construction, the Model 88 is compatible with corrosive
media and hazardous environments. With the cover
retained by a stainless steel chain and no internal
jumpers for span turndown, losses due to misplaced or
dropped parts are eliminated.
Pressure Transmitter
