NOSHOK 800 Series Platinum RTD Temperature Transmitter

A compact RTD temperature transmitter with 4-20 mA output

The NOSHOK 800 Series is a platinum resistance temperature transmitter. A 100 ohm platinum sensor (Class B per EN 60751 / IEC 751) is mounted in a 316 stainless steel stem and housing, and the electronics convert it to a 4-20 mA or voltage output. Standard ranges run from -40 F to 400 F, with burnout protection from 3.3 mA to 23 mA and reverse polarity, over-voltage and short circuit protection.

The 6 mm stem withstands up to 725 psi and the 8 mm stem 1,500 psi, and the housing is IP65 per EN 60529. The datasheet notes the transmitter is also available with the NOSHOK 1800 Series attachable loop indicator.

800 Series specification

Ordering codes: process connection 2 (1/4 inch NPT male), 8 (1/2 inch NPT male), 48 (1/2 inch NPT male with adjustable compression fitting); electrical 1 (DIN EN 175301-803 Form A with 36 inch cable), 8 (DIN EN 175301-803 Form A), 14 (Form A with ISO 4400 1/2 inch NPT female conduit), 25 (M12 x 1, 4-pin); stem lengths 025 (2.5 in), 040, 060, 090, 120 (12 in); stem diameters 6 mm or 8 mm.

Order code explained

Example: 800-50/300-1-1-8-8-040-6 means 50 to 300 F range, accuracy code 1 (Class B + 0.5% BFSL), 4-20 mA output (1), 1/2 inch NPT male process connection (8), DIN EN 175301-803 Form A electrical connection (8), 4 inch stem (040) and 6 mm stem diameter (6). Wiring for 4-20 mA on a DIN connector uses pin 1 (V+) and pin 2 (V-); on an M12 connector it uses pins 1 and 3.

Selection notes

• Measure the loop resistance: V min equals 10 V plus 0.020 A times the loop resistance, which includes sensor and wire resistance.
• Use a thermowell for pressure, corrosive fluids and high velocity, as the NOSHOK catalog recommends.
• Pick the stem length so the sensing tip is in the middle of the pipe or tank, and the 8 mm stem for pressures above 725 psi.
• Ambient limits of -40 to 85 C define where the electronics can sit.

Applications in Oman and the GCC

The datasheet lists water systems, storage tanks, industrial machinery, HVAC and refrigeration. In GCC chilled water and cooling circuits the 4-20 mA output feeds BMS and PLC inputs, while the 85 C ambient limit and IP65 housing suit plant rooms and outdoor risers if shaded. It is not an explosion-proof device, so do not place it in classified areas.

Wiring and loop design

The 4-20 mA version is a two-wire loop-powered device, so the supply must provide at least 10 V plus 0.020 A times the loop resistance. With a 250 ohm receiver, for example, this is 15 V minimum (derived from the datasheet load formula), and the transmitter works up to 30 V. The datasheet lists three-wire voltage outputs for controllers that prefer volts, with load limits of 5,000 ohm for 1-5 V and 10,000 ohm for 0-10 V. Burnout protection means a broken sensor drives the loop outside the 4-20 mA band, between 3.3 and 23 mA, so a controller can detect a fault. The sensor tolerance of Class B plus the 0.5 percent output tolerance together set the overall accuracy, so for tighter work add the two figures and confirm the total with the maker. A 100 ohm platinum sensor also changes by a known amount per degree, which is why the datasheet quotes the tolerance as a base value plus a term that grows with temperature. The adjustable compression fitting option (code 48) lets you set the immersion depth on site, which is helpful when pipe or tank wall thickness is not known in advance.

Selection and installation notes

A thermometer or temperature transmitter is selected from the range, the stem or bulb length, the connection and the ambient conditions. Fit it in a thermowell of the right bore and length so the sensing element reaches the flow, fill the well with heat-transfer paste where the maker advises, keep the cable or case clear of heat and vibration and check the reading against a reference instrument at commissioning and at regular intervals.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related items and documents

See also the NOSHOK 100 Series thermometer and our temperature instrumentation category. The datasheet is attached; Seven Star LLC can quote against your range, stem length and connector.

Related NOSHOK products: NOSHOK 400/500 Series All-Stainless Steel Pressure Gauge, NOSHOK 100 Series Industrial Bimetal Dial Thermometer, NOSHOK 1000 Series Piston Differential Pressure Gauge, NOSHOK 621/622 Explosion-Proof Pressure Transmitter, NOSHOK 628 Intrinsically Safe Hammer Union Pressure Transmitter and NOSHOK PTI20 Intelligent Pressure Transmitter with Display.