NOSHOK 100 Series Industrial Bimetal Dial Thermometer

A stainless steel bimetal dial thermometer built for process pipework

The NOSHOK 100 Series is a heavy-duty bimetal dial thermometer with a weather-resistant, tamper-proof 304 stainless steel case and bezel. A heat-treated bimetallic helix coil, silicone coated below 500 F to damp pointer vibration and speed response, drives an aluminum pointer over an anodized aluminum dial. The datasheet lists accuracy of +/-1% of full scale, Grade A per ASME B40.3, with a hermetic seal that is dustproof and leakproof per the same standard.

Four dial sizes (1-3/4, 2, 3 and 5 inch) all use a center back connection, and standard stem lengths run from 2-1/2 inch to 42 inch (up to 120 inch available). A 360 degree groove around the stem shows the minimum immersion point.

100 Series specification

Temperature ranges listed (examples): -100/100 F/C dual, -40/160 F/C, 0/140, 0/180, 0/220, 0/250, 20/240, 25/125, 50/300, 50/400, 50/500, 100/800 F, 150/750, 200/1000 F; single C scales include -70/70, -50/50, 0/100, 0/150, 0/200, 0/300, 0/400 and 100/550. Ranges 200/1,000 F and 100/500 C are not recommended for continuous use above 800 F (425 C).

Case dimensions: 18-110 dial 1.750 in (44.45 mm), stem 0.150 in; 20-110 dial 2.089 in (53.06 mm); 30-110 dial 3.187 in (80.95 mm) with 1.375 in (34.93 mm) case depth; 50-110 dial 5.040 in (128.02 mm) with 1.718 in (43.63 mm) case depth.

Order code explained

Example: 30-110-120-0/140 F/C-LL = 3 inch dial, back connection case type 110, 12 inch stem (120), 0 to 140 F/C dual scale, polycarbonate lens (LL). Options include 1/8 and 3/8 inch NPT (18-110 only), 6 or 8 mm stem and heavy-duty 0.375 inch stem (30-110 and 50-110 only), 316 stainless wetted parts, 1/2 inch NPT adjustable union, silicone fill (SL), stainless tagging and several lens types. The 18-110 model is offered only in 2-1/2, 4, 6, 8, 12, 15 and 18 inch stems.

Selection notes

• Choose a range so the normal temperature falls between 25 and 75 percent of the scale.
• Use a thermowell for pressure, corrosive fluids and high velocity, as the datasheet recommends.
• Silicone fill is limited to 20-110, 30-110 and 50-110 models and to ranges -50 F to 500 F; polycarbonate lens is standard with silicone fill.
• Immersion: submerge the stem past the groove mark so that the sensing part is fully in the medium.

Applications in Oman and the GCC

The datasheet suggests industrial process, petrochemical, food and beverage, commercial and wastewater uses. In GCC plants the sealed 304 case suits washdown, dust and humidity, and the heat range options cover hot-oil and steam lines up to 1,000 F with the continuous limit noted. Specify 316 wetted parts for coastal or chloride exposure.

Choosing stem length, range and options

Stem length is the part most often ordered wrong. The datasheet lists a groove around the stem as the minimum immersion mark, so the length you order must reach beyond that point in the pipe or vessel, which for a 6 inch pipe in a thermowell usually means a longer stem than the pipe diameter suggests. The 18-110 gauge has a thin 0.150 inch stem and is only offered in 2-1/2, 4, 6, 8, 12, 15 and 18 inch lengths, while the 20-110, 30-110 and 50-110 models use a 0.250 inch stem and the larger two can take a heavy-duty 0.375 inch stem (HD) for vibration or velocity. Dual scale F/C dials, such as 0/140 F/C, are convenient where drawings use Celsius and operators think in Fahrenheit. The adjustable union (AU) option lets you rotate the dial to face the operator after the stem is threaded in. Silicone fill and a polycarbonate lens suit vibration and outdoor use, but not every range, so check the footnotes before ordering.

When you enquire about the 100 Series, give the dial size from the 1-3/4 to 5 inch choices, the temperature range, the stem length up to the 42 inch limit and the fitting style, so that the Grade A bimetal thermometer can be configured from the datasheet ordering codes.

Selection and installation notes

A dial thermometer is chosen from the temperature range, the dial size, the stem length and the connection. Fit it in a thermowell of the right bore and length so the stem reaches the flow and does not touch the well bottom, choose an angle or a back connection that lets the dial be read from the normal position, avoid vibration and keep the case clear of heat and condensation. Check the reading against a reference thermometer from time to time.

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 our temperature instrumentation category and the NOSHOK 800 Series temperature transmitter. The datasheet is attached; Seven Star LLC can quote against your dial size, stem length and range.