Equities in the electrical sector were under pressure on Friday after instrumentation and controls company Spectris gave a gloomy first-quarter update and scaled back guidance for the full year.FTSE 250 firm Spectris said that sales in the first three months of the year were down 9.0% on a constant currency basis, worse than analysts' (and its own) forecasts, due to a strong prior-year comparative and weaker consumer confidence which led to deferral of orders and shipment delays.The company, which is involved in materials analysis, test and measurement, in-line instrumentation and industrial contolrs, said that tough trading was noted across all its major regions, reporting segments and majority of end markets.While Spectris said its full-year performance will be broadly in line with expectations, top-line growth in 2013 is now expected to be lower it previously thought.The stock was down 14.47% at 1,903p in afternoon trade, trading at levels not seen since late November 2012.Analysts at Jefferies maintained their 'buy' rating for the shares today despite the disappointment but admitted that consensus earnings estimates will likely be lowered by low- to mid-single-digit rates. They said: "A degree of uncertainty will also exist until there is more comfort in an improved 2Q13 performance (sales and orders)."Sector peer Renishaw, which works in the measurement, motion control, spectroscopy and precision machining industries, was falling in sympathy, down 5.72% at 1,550p. Electric peers Laird and Oxford Instruments were also firmly lower.Top performing sectors so far todayIndustrial Metals & Mining 1,725.65 +2.08%Automobiles & Parts 6,013.51 +2.06%Forestry & Paper 9,101.80 +1.26%Mining 16,237.37 +1.21%Banks 4,631.18 +1.11%Bottom performing sectors so far todayElectronic & Electrical Equipment 3,637.72 -6.31%Technology Hardware & Equipment 1,028.55 -0.96%Aerospace and Defence 4,661.48 -0.86%Food & Drug Retailers 4,489.16 -0.62%Industrial Engineering 8,812.67 -0.61%BC